The male gonads are carried on the radial canals.
solid larval tentacles, re Radial nerve.
As medusae are known to bud medusae from the radial canals there is nothing impossible in Aliman's theory, but it cannot be said to have; received satisfactory proof.
In Willia, Geryonia, &c., however, the tentacles and radial canals are on the plan of six instead of four (figs.
The marginal tentacles are rarely absent in non-parasitic forms, and are typically four in number, corresponding to the four perradii marked by the radial canals.
Immediately on the‘ formation of the Canadian Pacific railway company branch lines were begun at Winnipeg and there are eight radial lines running from this centre to all parts of the country.
Across the arc is a transverse or radial magnetic field, and the electrodes are connected by an oscillatory circuit consisting of a condenser and inductance.
Its proximal end forms a shallow cup for articulation with the outer condyle of the humerus; the distal end bears a knob which fits into the radial carpal.
If then the screw-value in kilometres per second is known for the neighbourhood of each of the comparison lines employed, the radial velocity of the star can be independently derived directly from coincidences made in above manner in the neighbourhood of each comparison line.
The radial canals may be simple or branched, primarily four, rarely six in number.
that is to say, in a radial direction from, or (in the manubrium) parallel to, the same ideal axis.
- Tropho- some unknown; gonosome, free medusae, with deep, bell-shaped umbrella, with interradial gonads on the base of the stomach, with branched radial canals, and correspondingly numerous hollow tentacles.
- Tropho so m e with stalked hydrothecae; gonosome, free medusae with otocysts and four, rarely six or eight, unbranched radial canals.
- Trophosome only known in one genus (Thaumantias), similar to that of the Eucopidae; gonosome, free medusae with otocysts inconspicuous or absent, with usually four, sometimes eight, rarely more than eight, radial canals, simple and unbranched, along which the gonads are developed, with numerous tentacles bearing ocelli and with marginal sense-clubs.
Amphogona, hermaphrodite, with male and female gonads on alternating radial canals.
In this order the radial canals are represented only by wide gastric pouches, and in the family Solmaridae are suppressed altogether, so that the tentacles and the festoons of the ring-canal arise directly from the stomach.
The medial portion forms radiating tracts of fibres, the so-called " bell-muscles " running underneath, and parallel to, the radial canals; when greatly developed, as in Tiaridae, they form ridges, so-called mesenteries, projecting into the sub-umbral cavity.
Buds may be produced from the manubrium, radial canals, ring-canal, or tentaclebases, or from an aboral stolon (Narcomedusae).
Hence the gonads are found on the manubrium in Anthomedusae generally; on the base of the manubrium, or under the gastral pouches, or in both these situations (Octorchidae), or under the radial canals, in Trachomedusae; under the gastral pouches or radial canals, in Narcomedusae.
E, Transverse sec- r.c. Radial canal.
He defined them as possessing radial instead of bilateral symmetry, and as apparently destitute of nervous system and sense organs, as having the circulatory system rudimentary or absent, and the respiratory organs on or coextensive with the surface of the body; he included under this title and definition five classes, - Echinodermata, Acalepha, Entozoa, Polypi and Infusoria.
The stomach may be altogether lodged in the manubrium, from which the radial canals then take origin directly as in Geryonia (Trachomedusae); it may be with or without gastric pouches.
preceded by six per cartilaginous margin of the radial and six interradial disk centripetally in the solid larval tentacles).
- Trophosome unknown; gonosome, free medusae of deep form, with radial canals branched in a feathery manner, and After Haeckel, System der Medusen, by permission of Gustav Fischer.
The manubrium bearing the gonads is mouthless, and the umbrella is without tentacles, sense-organs, velum or radial canals.
not lobed or indented; tentaculocysts usually enclosed in vesicles; gonads on the radial canals.
The gonads are on the radial canals or on the stomach (Ptychogastridae), and each gonad may be divided into two by a longitudinal sub-umbral muscle-tract.
- Four radial canals, four gonads; stomach not prolonged into the manubrium, which is relatively short; tentaculocysts free.
Olindiadae, with four radial canals and four gonads; manubrium short; ring-canals giving off blind centripetal canals; tentaculocysts enclosed.
Eight radial canals, eight gonads, stomach not prolonged into manubrium; tentaculocysts enclosed.
Eight radial canals, two, four or eight gonads; tentacles numerous; tentaculocysts free; stomach prolonged into manubrium.
Four or six radial canals; gonads band-like; stomach prolonged into a manubrium of great length; tentaculocysts enclosed.
Eight very broad radial canals; ex-umbrella often provided with lateral outgrowths; tentacles differing in size, but in a single row.
The radial canals are represented by wide gastric pouches, and may be absent, so that the tentacles arise directly from the stomach (Solmaridae).
Endodermal cell of Phanerogam, with suberized central band on radial and transverse walls.
This may have a radial stem-like organization, a central cell-thread giving off from every side a number of short sometimes unicellular branches, which together form a cortex round the central thread, the whole structure having a cylindrical form which only branches when one of the short cell-branches from the central thread grows out beyond the general surface and forms in its turn a new central thread, from whose cells arise new short branches.
All types of valves are with few exceptions operated by a link motion, generally of the Stephenson type, occasionally of the Allan type or the Gooch type, or with some form of radial gear as the Joy gear or the Walschaert gear, though the latter gear has characteristics which ally it with the link motions.
We can distinguish (I) digestive endoderm, in the stomach, often with special glandular elements; (2) circu-, latory endoderm, in the radial and ring canals; (3) supporting endoderm in the axes of the tentacles and in the endodermlamella; the latter is primitively a double layer of cells, produced by concrescence OC-- = w.?"
The next step is illustrated by the female gonophores of Cladocoryne, where the radial and ring-canals F G H Modified from Weismann, Entstehung der Sexualzellen bei den Hydromedusen.
In some Leptomedusae the gonads are formed on the radial canals and form protruding masses resembling sporosacs superficially, but not in structure.
becomes a vesicle, the future r.c, Radial canal.
Trophosome (only known in one genus), polyps with two tentacles forming a creeping colony; gonosome, free medusae with four, six or more radial canals, giving off one or more lateral branches which run to the margin of the umbrella, with the stomach produced into four, six or more lobes, upon which the gonads are developed; the mouth with four lips or with a folded margin; the tentacles simple, arranged evenly round the margin of the umbrella.
manubrium and In C the marsupium (m) is formed as finger-like another below the process from the summit of the blastostyle, en closing the acrocyst; b, medusa-buds on the radial canal in blastostyle.
- Trophosome only known in one genus (Polycanna), and similar to the preceding; gonosome, free medusae with otocysts and with at least eight radial canals, often a hundred or more, simple or branched.
- Trophosome unknown; gonosome, free medusae, with four or six radial canals, bearing the gonads, with numerous tentacles, between which occur sense-clubs, without otocysts.
68, k), absent in Chondrophorida and Cystophorida; they are contractile and resemble, both in appearance, structure and function, the umbrella of a medusa, with radial canals, ring-canal and velum; but they are without manubrium, tentacles or sense-organs, and are always bilaterally symmetrical, a peculiarity of form related with the fact that they are attached on one side to the stem.
c eun~7 Such an arrangement of vascular tissue is called radial, ~
The radial structure is characteristic of all root-steles, which have in essential points a remarkably uniform structure throughout the vascular plants, a fact no doubt largely dependent on the very uniform conditions under which they live.
When a given initial cell of the cambium has once begun to produce cells of this sort it continues the process, so that a radial plate of parenchyma cells is formed stretching in one plane through the xylem and phloem.
The sieve-tubes of the secondary phloem usually have very oblique end-walls bearing a row of sieve-plates; plates also occur on the radial side-walls.
Above this knob is often present an ectepicondylar process whence arise the tendons of the ulnar and radial flexors.
r', u', Radial and ulnar carpal bones; with the three digits I., II., III.
The flexor digitorum sublimis muscle arises fleshy from the long elastic band which extends from the inner humeral condyle along the ventral surface of the ulna to the ulnar carpal bone, over which the tendon runs to insert itself on the radial anterior side of the first phalanx of the second digit.
The hind-wings, when developed, are characteristic in form, possessing a sub-costal nervure with which the reduced radial nervure usually becomes associated.
At this fold the median nervure stops and is joined by a cross nervure to the radial, which can be distinguished throughout its length from the subcostal.
Engines of this class, with 78-inch driving wheels and the leading axle fitted with Webb's radial axle-box, for many years did excellent work on the London & North-Western railway.
He initiated in 1866 the spectroscopic observation of sunspots; applied Doppler's principle in 1869 to determine the radial velocities of the chromospheric gases; and successfully investigated the chemistry of the sun from 1872 onward.
3, Then comes the radial - usually 4 the most important nervure of the wing - typically with five branches, and the median with four.
Males of the Argyopidae hang on the outskirt s of the webs of the females and signal their presence to her by jerking the radial threads in a peculiar manner.
Close to the source the stream lines will be radial lines.
lar; 3, 4, 5, 6, radial or sub4.
The main median nervure, and usually also the sub-costal become united with the radial, while the branches of radial, median and cubital nervures pursuing a transverse or recurrent course across the wing, divide its area into a number of areolets or " cells," that are of importance in classification.
This wheel is mounted on a carrier which, being movable about its centre by a screw gearing worked by hand, gives a radial sweep to the cutting edges.
The radial distance x is at any instant proportional to the force acting through the spring.
Let us suppose that the rod is circular, of radius r, and that the radial displacement of the surface is r t.
The longitudinal extension is dy/dx, and therefore the radial contraction is n/r= udy/dx.
If r is of the order of A, n is of the order of y; and the kinetic energy of the radial motion is of the same order as that of the longitudinal motion.
Bells may be regarded as somewhat like circular plates vibrating with radial nodes, and with the edges turned down.
Ordinarily when a bell is struck the impulse primarily excites the radial motion, and the tangential motion follows as a matter of course.
When a finger-glass (an inverted bell), is excited by passing the finger round the circumference, the tangential motion is primarily excited and the radial follows it.
t, tentacle; g.p, gastric pouch; r.c, radial canal not present in C and C'; c.c, circular or ring-canal; e.1, endoderm-lamella formed by concrescence.
The medusa has a pronounced radial symmetry, and the positions of the primary tentacles, usually four in number, mark out the so-called radii, alternating with which are four interradii.
Besides the circular subumbral muscles, there may be others running in a radial direction, chiefly developed as the longitudinal retractor muscles of the manubrium.
r.c. Radial canal.
From the stomach, canals arise termed the radial canals (r.c.); typically four in number, they run in a radial direction to the edge 2 For other variations of the medusa, often of importance for systematic classification, see Hydromedusae and Scyphomedusae.
There the radial canals are joined by a ringcanal (c.c.) which runs round the margin of the umbrella.
i), they are formed on the subumbral surface, either on the manubrium or under the stomach or under the radial canals, or in more than one of these regions.
The stomach may be situated in the disk, or may be drawn out into the base of the manubrium, so that the disk is occupied only by the radial canals.
On the other hand the stomach may have lobes extending to the ring-canal, so that radial canals may be very short or absent.
The radial canals may be four, rarely six, or a multiple of these numbers, and may be very numerous.
More usually each cathamma is a wide triangular area, reducing the peripheral portion of the coelenteron to the four narrow radial canals and the ring-canal above described.
the radial and the median.
All the wings are of firm, glassy texture, and very complex in their neuration; a remarkable and unique feature is that a branch of the radius (the radial sector) crosses the median nervure, while, by the development of multitudinous cross-nervules, the wing-area becomes divided into an immense number of small areolets.
The grounds for this view are the radial symmetry of several Polyclads and the supposed origin of gonads and excretory flame-cells from the walls of gut, the occurrence of nematocysts in Anonymus, one of the most radially constructed Polyclads, and lastly the presence of two peculiar animals Ctenoplana and Coeloplana, which suggests a transition from Ctenophora to Polyclads.
3, where an outer aluminium ring, A A, is connected by 32 radial FIG.
6, the flow is what is called mixed, that is, it is partly a radial inward and partly an axial flow machine.
On entering, the water flows at first in a radial direction, and then gradually, as it passes through the wheel, it receives a downward component which becomes more and more important.
Bort (or Boart) is the name given to impure crystals or fragments useless for jewels; it is also applied to the rounded crystalline aggregates, which generally have a grey colour, a rough surface, often a radial structure, and are devoid of good cleavage.
The lines of flow in this method are radial.
Dorsiventrality is also clearly derived from radial construction, and anatropy of the ovule has followed atropy.
In Monocotyledons a similar advance from hypogyny to epigyny is observed, and from the dorsiventral to the radial type of flower.
The method once exclusively used consists in mixing the raw materials with a large quantity of water in a wash mill, a machine having radial horizontal arms driven from a central vertical spindle and carrying harrows which stir up and intermix any soft material placed in the pit in which the apparatus revolves.
Much of the character of organisms is due to various symmetries, radial, bilateral, metameric and so forth, and these symmetries arise, partly at least, from the mode of growth by cell division and the marshalling of groups of cells to the places where they are destined to proliferate.
The agreement is too close to be dismissed as a mere coincidence, and it is confirmed by a corresponding agreement of their radial motions determined by the spectroscope; and yet, seeing that a and Ursae Majoris are 19° apart, these two stars must be distant from each other at least one-third of the distance of each from the sun; thus the members of this singular group are separated by the ordinary stellar distances, and probably each has neighbours, not belonging to the system, which are closer to it than the other four stars of the group. Further, E.
The greatest radial velocities that have yet been found are about 60 m.
per second; several stars (Groombridge 1830 among them) have radial speeds of this amount.
A better method is to derive the speed from the radial motions observed with the spectroscope.
Campbell from the radial motions of 280 stars found the velocity to be 20 kilometres per second with a probable error of 12 km.
The radial resolution gives dr fdO\2
A point on a central orbit where the radial velocity (drfdt) vanishes is called an apse, and the corresponding radius is called an apse-line.
R is the radial component of force, is the moment about a lilie through 0 perpendicular to the plane ZOP, and 4 is the moment about OZ.
the acceleration of C, the radial n acceleration of B about C and the A
Let A be any origin, and let Ac represent the acceleration of the b point C, Ct the radial acceleration of B about C which must be in a direction parallel to BC, and tb the tan gential acceleration of B about C, C
The directions of the radial and tangential accelerations of the point B are always known when the position of the link is assigned, since these are to be drawn respectively parallel to and at right angles to the link itself.
The magnitude of the radial acceleration is given by the expression vi/BC, v being the velocity of the point B about the point C. This velocity can always be found from the velocity diagram of the chain of which the link forms a part.
In applying this principle to the drawing of an acceleration diagram for a mechanism, the velocity diagram of the mechanism must be first drawn in order to afford the means of calculating the several radial accelerations of the links.
Towards the end of the body both neural and haemal arches are continued into forked radial cartilages, which support a median fin.
At first, it seems, the Goltz plan of a defensive concentration there, to be followed by radial attacks on divided enemies, was adhered to by the Turks.
The city is divided into twelve radial systems, each with a pumping station, and the drainage is forced through five mains to eighteen sewage farms, each of which is under careful sanitary supervision, in respect both of the persons employed thereon, and the products, mainly milk, passing thence to the city for human consumption.
The eight adradial gonads on the subumbral walls of the four radial pouches, representing primitively four horse-shoeshaped gonads each divided into two by an interradial septum.
Finally in the majority of Scyphomedusae the primitively simple concrescence-areas become increased in number and in extent, so that radial canals, ring-canals, &c., can be distinguished in addition to stomachpouches.
which, however, are inter- v, Axial or gastric portion of the radial in position.
stomach or its pouches arise gv, Radiating and anastomosing sixteen radial canals, four canals of the enteric system.
a radial vertical plane so as B, Inferior or adoral olfactory to pass through the long axis of_the tentaculocyst.
very complicated; sixteen radial canals.
In Lychnorhizidae only eight of the sixteen radial canals reach the ring-canal; the genus Crambessa is the best-known representative of the family.
In the other two families there are eight radial canals, and between them a network of canals with many openings into the ring-canal.
Apart from the numerous parasitic forms, the only Crustacea which have adopted a strictly sedentary habit of life are the Cirripedia, and here, as elsewhere, profound modifications of structure have resulted, leading ultimately to a partial assumption of the radial type of symmetry which is so often associated with a sedentary life.
The pith is encircled by a cylinder of secondary wood, consisting of single or multiple radial rows of tracheids separated by broad medullary rays composed of large parenchymatous cells; the tracheids bear numerous bordered FIG.
pits on the radial walls.
The secondary phloem contains numerous thick-walled fibres, parenchymatous cells, and large sieve-tubes with plates on the radial walls; swollen parenchymatous cells containing crystals are commonly met with in the cortex, pith and medullary-ray tissues.
The wood consists of tracheids, with circular bordered pits on their radial walls, and in the late summer wood pits are unusually abundant on the tangential walls.
The sudden termination of the secondary tracheids against the pith-cells may afford evidence of root-structure as distinct from stem-structure, in which the radial rows of secondary tracheids pass into the irregularly-arranged primary elements next the pith.
It is in the nature of the secondary xylem that the Coniferales are most readily distinguished from the Dicotyledons and Cycadaceae; the wood is homogeneous in structure, consisting almost entirely of tracheids with circular or polygonal bordered pits on the radial walls, more particularly in the late summer wood.
In a radial section of a pine stem each ray is seen to consist in the median part of a few rows of parenchymatous cells with large oval simple pits in their walls, accompanied above and below by horizontal tracheids with bordered pits.
The pits in the radial walls of the ordinary xylem-tracheids occur in a single row or in a double row, of which the pits are not in contact, and those of the two rows are placed on the same level.
In the Araucarian type of wood (Araucaria and Agathis) the bordered pits, which occur in two or three rows on the radial walls of the tracheids, are in mutual contact and polygonal in shape, the pits of the different rows are alternate and not on the same level; in this type of wood the annual rings are often much less distinct than in Cupressus, Pinus and other genera.
We find on the left-hand scale of yield that the height of the ordinate drawn to the 50-inch mean rainfall curve from 200,000 on the capacity scale, is 1457 gallons per day per acre; and the straight radial line, which cuts the point of intersection of the curved line and the co-ordinates, tells us that this reservoir will equalize the flow of the two driest consecutive years.
Similarly, if we wish to equalize the flow of the three driest consecutive years we change the co-ordinates to the radial line figured 3, and thus find that the available capacity of the reservoir must be 276,000 gallons per acre, and that in consideration of the additional expense of such a reservoir we shall increase the daily yield to 1612 gallons per acre.
In this case the left-hand radial line passes through the point at which the coordinates meet, showing that the reservoir will just equalize the flow of the driest year.
The circular drum is divided into four equal compartments by radial diaphragms. And in a pan at the other end of the beam (which is counter - balanced for the weight of the drum) is a I-lb weight to weigh the tea.
In Actinia, as in all Anthozoan zooids, the coelenteron is not a simple cavity, as in a Hydroid, but is divided by a number of radial folds or curtains of soft tissue into a corresponding number of radial chambers.
These radial folds are known as mesenteries, and their position and relations may be understood by reference to figs.
Favosites hemisphaerica a number of radial spines, projecting into the cavity FIG.
The cavities both of the calices and coenenchymal tubes of Heliopora are closed below by horizontal partitions or tabulae, hence the genus was formerly included in the group Tabulata, and was supposed to belong to the madreporarian corals, both because of its lamellar skeleton, which resembles that of a Ma.drepore, and because each calicle has from twelve to fifteen radial partitions or septa projecting into its cavity.
(2) The septa, radial plates of FIG.
The cells forming the limbs of the ectodermic folds secrete nodules of calcite, and these, fusing together, give rise to six (or twelve) vertical radial plates or septa.
This arrangement, however, is by no means characteristic even of the Zaphrentidae, and in the family Cyathophyllidae most of the genera exhibit a radial symmetry in which no trace of the bilateral arrangement described above is recognizable, and indeed in the genus Cyathophyllum itself a radial arrangement is the rule.
of Thecidiosmilia, two septa, corresponding to the mainand counter-septa of Streptelasma, are first formed, then two alar septa, and afterwards the remaining septa, the latter taking on a generally radial arrangement, though the original bilaterality is marked by the preponderance of the main septum.
- Mainly colonial, rarely solitary corals, with radial septa, but bilateral arrangement indicated by persistence of a main septum.
Septa numerous, generally radial, seldom pinnate.
Septa radial; dissepiments present; an epitheca surrounds the base of massive or maeandroid forms, but only surrounds individual corallites in simple or branching forms. Typical genera - Goniastraea, M.
- Solitary and colonial corals, with numerous radial septa united by synapticulae.
Septa radial; the primary septa usually compact, the remainder perforate.
Each plate of the upper circlet supports an arm, and is called a "radial"; the plates of the lower circlet, the "basals," rest on the stem and alternate with those of the upper circlet, i.e.
For, if these radial constituents of the supposed apical system in an ophiurid have really some other origin, why can we not say the same of the supposed basals?
Early in the life-history of Synapta occurs a stage with five tentacles around the mouth, and into these pass canals from the water-ring, the radial canals to the body-wall making a subsequent, and only temporary, appearance (fig.
Study of the earliest larval stages has always led to the conclusion that the Echinoderms must have descended from some freely-moving form with a bilateral symmetry, and, connecting this with the ideas just mentioned, we reach the conception that this supposed bilateral ancestor (or Dipleurula) may have become fixed, and may have gradually acquired a radial symmetry in consequence of its sedentary mode of life.
It might be possible to prove the origin of all classes from Pelmatozoa, without thereby explaining the origin of such fundamental features as radial symmetry, the developmental metamorphosis, and the torsion that affects both gut and body-cavities during that process; but the acceptance of a Dipleurula as the common ancestor necessitates an explanation of these features.
Although, in the extreme correlation of the radial food-grooves, nerves, watervessels, and so forth, with a radiate symmetry of the theca, such a type differs from the Cystidea, while in the possession of jointed processes from the radial plates, bearing the grooves and the various body-systems outwards from the theca, it differs from all other Echinoderms, nevertheless ancient forms are known which, if they are not themselves the actual links, suggest how the crinoid type may have been evolved from some of the more regular cystids.
Beneath each food-groove was a radial water-vessel and probably a nerve and blood-vessel, all which structures passed either between certain regularly arranged thecal plates, or along a furrow floored by those plates, which were then in two alternating series.
So too the explanation of radial symmetry and torsion of organs as due to a Pelmatozoic mode of life finds confirmation in many other phyla.
Since this must have, on our theory, enclosed the parietal canal from the anterior coelom, it is possible that the genital products were developed from the lining cells of that cavity, and that the genital pore was nothing but its original pore not yet united with that from the water-sac. The concrescence of these pores can be traced in other cystids; but as the genital organs became affected by radial symmetry the original function of the duct was lost, and the reproductive elements escaped to the exterior in another way.
The crinoid type was differentiated by the extension of the food-grooves and associated organs along radial outgrowths from the theca itself.
These constituted the arms (brachia), and five definite radial plates of the theca were specialized for their support.
(Adapted from Jaekel.) grooves, no longer needed for the collection of food, closed over, and are still traceable as ciliated canals overlying the radial nerves.
All living, and most extinct, Echinoderms show the following features, almost certainly due to an ancestral pelmatozoic stage: - An incomplete radial symmetry, of which five is usually the dominant number, is superimposed on the secondary bilateralism, owing to the outgrowth from the mouth region of one unpaired and two paired ciliated grooves; these have a floor of nervous epithelium, and are accompanied by subjacent radial canals from the water-ring, giving off lateral podia and thus forming ambulacra, and by a perihaemal system of canals apparently growing out from coelomic cavities.
- Pelmatozoa in which radial polymeric symmetry of the theca is developed either not at all or not in complete correlation with the radial symmetry of the ambulacra (such as obtains in Blastoidea and Crinoidea); in which extensions of the food-grooves are exothecal or epithecal or both combined, but neither endothecal nor pierced by podia (as in some Edrioasteroidea).
- Radial symmetry has affected neither food-grooves nor thecal plates; nor, probably, nerves, ambulacral vessels, nor gonads.
- Radial symmetry affects the food-grooves and, in the more advanced families, the thecal plates; probably also the nerves and ambulacral vessels, but not the gonads.
- Radial symmetry affects the food-grooves, and by degrees the thecal plates connected therewith, but not the interradial thecal plates; probably also the nerves and ambulacral vessels, but not the gonads.
The thecal plates, however irregular in some species, always show defined basals and a distinct plate ("radial") at the end of each ambulacrum; they are in all cases so far affected by pentamerous symmetry that their sutures never cross the ambulacra.
- Crinoidea in which the base consists of BB and IBB, the latter being liable to atrophy or fusion with the proximale, but the aboral prolongations of the chambered organ are always radial; new columnals may or may not be introduced at the proximal end of the stem.
Such a form gave rise to descendants differing inter se as regards the suppression of the radial canals and of the podia, the form of the tentacles, and the development of respiratory trees.
- Radial canals supplying tentacles and podia.
- Neither radial canals nor podia.
The radial water-vessels lie in grooves on the ventral side of flooring-plates (usually called "ambulacrals"); they and their podia are limited to the oral surface of the body and their extremities are separated from the FIG.
- Ambulacrals not yet forming complete vertebrae; plates of disk not yet specialized into mouth, radial or genital shields.
- Ambulacral pairs fused to form vertebrae with definite articular surfaces; mouth, radial and genital shields developed, though not all need be present in any one form.
In other instances, notably in the lemurs, but also in certain carnivora, rodents and marsupials, they occupy a position on the fore-arm near the wrist, in connexion with glands, and receive sensory powers from the radial nerve.
maximum, where some short tracheides, arranged in radial rows, arise from a cambium.
spinosa) the radial stele has a number of protoxylem groups arranged round the periphery, much as in Lepidodendron.
In the roots of Ophioglossum and Botrychium and in the first formed roots of Helminthostachys an endophytic fungus is present, forming a mycorhiza - the stele in the larger roots has the usual radial arrangement of xylem and phloem; monarch roots occur in Ophioglossum.
He employed in his discussion the radial velocities of 280 stars, spectroscopically determined; and the upshot signally exemplified the community of interests between the rising science of astrophysics and the ancient science of astrometry.
He employed it, with an outcome of striking promise, to measure the radial speed of some of the brighter stars.
Not only the grosser facts concerning radial velocity, but variations in it so small as a mile, or less, per second, have been recorded and interpreted in terms of deep meaning.
The radial or fan-shaped markings known as Oldhamia were first detected in this series, but are now known from Cambrian beds in otter countries; in default of other satisfactory fossils, the series of Bray and Howth has long been held to be Cambrian.
This concentration is most easily produced by sliding or revolving diaphragms. A series of holes of different sizes perforate a revolving disk below the stage plate at an equal radial distance from the axis of the disk, so that the holes can be brought under the preparation in turn, the centre of the diaphragms always being a continuation of the optical axis of the microscope.
In contrast with this are polysymmetrical or actinomorphic flowers, which have a radial symmetry and can be divided by several planes into several exactly similar portions; such are all regular, symmetrical flowers.
In all the larger specimens a broad zone of wood, with its elements in radial series, had been added.
B entirely of radial bands of tracheides interspersed with medullary rays.
The pitting of the tracheides is more or less scalariform in character, and is limited to the radial walls.
In Calamodendron (Upper Coal Measures) the wood has a more complex structure than in Calamites, the principal rays including radial tracts of fibrous tissue, in addition to the usual parenchyma.
C. Grand' Euryi, Ren.) radial membranous plates hung down from each verticil of bracts, forming compartments in which the subjacent sporangio phores were enclosed.
The seed-like body was detached as a whole from the cone, and in this condition was known for many years under the name of Cardiocarpon anomalum, having been wrongly identified with a true Gymnospermous seed so named a seed are obvious; the which is not tubular, but forms a long crevice, running in a direction radial to the strobilus.
Radial longitudinal section of seed-like organ.
Many other forms of seed, and especially those which show radial symmetry, as for example Trigonocarpus, Stephanospermum and Lagenostoma belonged, as we have seen, to some of the plants grouped under Pteridospermeae, though other Pteridosperms had flattened seeds not as yet distinguishable from those of Cordaitales.
arbour also have a range of arbors including a radial arbor.
muscles biceps - The biceps tendon attaches to the radial tuberosity on the inside of the upper radius.
The front brakes use a radial caliper with four opposed pistons, in keeping with the latest trends in racing technology.
This caliper will fit directly to any Japanese bike that has radial calipers fitted as standard.
calliper had to modify it quite extensively to get my radial mount calipers to fit and to get steering arms on.
UMD Radial Cleaner: With their own protective casing, UMDs are hard to clean.
clutch; A new, radial clutch master cylinder has been specially developed for the Super Duke.
commutey seven per cent of all radial commuting journeys were for work.
coronagraph images will provide electron densities, or the number of electrons per unit volume, specifying their global distribution and radial variation.
We have simply set the cutoff equal to the minimum between the first and second peaks in the liquid radial distribution function.
He talked about tangential energy and radial energy and most of us who were scientists really rather demurred from that.
droid's radial menu, and select " Follow Me " .
ellipse tools and tools for drawing joined and radial lines.
The six paneled door has a radial fanlight around which is a scalloped molded pattern within the pediment.
fistula between the radial artery and an adjacent vein in 1966.
spiral flexures - These are flat springs with high radial stiffness allowing maintenance of the close tolerances required for the clearance seals.
These include forged aluminum gear and brake levers, die cast aluminum footrest mounts, an aluminum silencer, and tubeless radial tires.
Associated soft tissue defects were repaired using radial forearm (n = 22) or rectus abdominis (n= 5) free flaps.
radial glia are only found during fetal development, but these insights indicate that they may have the potential to convert into stem cells.
Nature of problem: This program reads the radial integrals stored on a permanent tape or disk file by RMATRX STG1.
For example: radial keratotomy, a surgery to correct vision, was performed in rabbits prior to humans.
Anarchic, hypercellular cortices with disruption of normal cortical lamination and radial alignment of neurones are the striking low-power features.
The Influence of Tree Canopy An often overlooked point when calculating tree shadow lengths is the radial distance of the crown spread.
This radial ley gradually fanned out over a distance with the result that several kilometers of Strathardle became affected by unhealthy radiations.
The engine is mounted sideways on a radial mount bolted to the front 1/4 inch ply bulkhead.
New fork boots with centrally mounted axle (no offset) hold the radial brakes as well as the new splash sand fork protectors.
False Blood should not pulsate as it leaves the radial artery?
Assumed to be the same for medium urban radial as for large urban radial The Vicario work was based on surveys of 2000 travelers.
Irving was anxious to prove the superiority of the new radial valved Python engine, and entered an outfit in the 1932 Lands End.
The rural radial is also loss making, with high fares and very low patronage.
radial velocity The speed at which an object is moving away or toward an observer.
radial caliper with four opposed pistons, in keeping with the latest trends in racing technology.
radial keratotomy, a surgery to correct vision, was performed in rabbits prior to humans.
radial spokes may require an alternate spoke magnet.
radial 4-pot opposed piston calipers deliver impressive stopping performance with excellent feel at the lever.
radial ply tires, with flexible side walls may touch under load.
Also related: make a transparent, hand cranked, centrifugal water pump (with purely radial impeller blades to keep explanation simple ).
Keith Prime took 4th on his 640cc Rudge Special, with Robert Rushton making a welcome appearance on his fully radial Ulster taking 5th.
All metal CNC machined alloy swashplate with precision radial bearing and hard chromed PTFE lined center swivel ball.
Like the Lancaster it was initially fitted with Rolls Royce Merlins but subsequent variants used the excellent Bristol Hercules sleeve valve radial engines.
The small town radial is struggling with low margins and high fares.
The similarity of bulk and cluster radial distribution functions can easily be understood within the polytetrahedral model of liquid structure.
radial (arm) sawthat power switches on radial arm saw, etc. was on and positioned for the right-handed users.
Axial internal stresses due to thermal expansion mismatch and cure shrinkage were taken into account, but radial stresses were ignored.
The wheel magnet attaches to conventional three crossed spoke pattern wheels, bladed or radial spokes may require an alternate spoke magnet.
The eighth and final event was a recovery to Valley along a specified radial from the Valley TACAN, wearing a correct IFF squawk.
The program produces a plot of completeness vs. resolution and a plot of the average radial completeness in polar coordinates theta and phi.
Students learn who wrote the first computer program, who discovered pulsars, who invented radial tires, science puzzles and much more!
Examples include measuring the total transmittance and reflectance or by measuring the radial spatial distribution.
R radial velocity The speed at which an object is moving away or toward an observer.
The machine purports to give the central arterial waveform from the measured radial artery pressure waveform.
weathered granite took place as a generally radial drainage network evolved around the granite dome.
Stable Encoding of Robot Trajectories using Normalized Radial Basis Functions: Application to an autonomous wheelchair.
In Geryonia, centripetal canals, ending blindly, arise from the ring-canal and run in a radial direction towards the centre of the umbrella (fig.
form the radial canals (r.c.), ring-canal (c.c.), and endoderm-lamella (e.l., fig.
In the Stylasteridae sessile gonophores are formed, always by budding from the coenosarc. In Distichopora the gonophores have radial canals, but in other genera they are sporosacs with no trace of medusoid structure.
The radial canals are four, six, eight or more, and in some genera blindly-ending centripetal canals are present (fig.
Liriope, &c., with four radial canals; Geryonia, Carmarina (fig.
Radii a multiple of four, with radial gastric pouches bifurcated or subdivided; the tentacles are implanted in the notch between the two subdivisions of each (primary) gastric pouch, hence the (secondary) gastric pouches appear to be " internemal " in position, i.e.
This layer has its cells closely united and sealed to one another, so to speak, by the conversion of the radial and transverse walls (which separate each cell from the other cells of the layer), or of a band running in the centre of these, into corky substance (fig.
The top and bottom rows of the xylem rays are often developed as irregularly-thickened radially-elongated tracheids which serve for the radial conduction of water, and communicate with the ordinary tracheids of the secondary xylem by large bordered pits.
Where the primary bundles are farther apart, so that the primary rays are wider, the interfascicular cambium may form several fairly broad (principal) secondary rays in continuation of certain radial bands of the primary ray, and between these, wedges of secondary xylem and phloem: or, finally, secondary xylem and phloem may be formed by the whole circumference ot the cambium, fascicular and interfascicular alike, interrupted only by narrow secondary rays, which have no relation to the primary ones.
Again some species of Dictyna, belonging to the Amaurobiidae, also have a tubular retreat opening on to the surface of a snare in which a crude attempt at a radial and concentric arrangement of the threads is perceptible.
In the genus Rhizostoma, common on the British coasts and conspicuous on account of its large size, the oral arms, originally distinct and four in number, undergo concrescence, so that the entrance to the mouth is reduced to numerous fine pores and canals.2 Like the external structure, the internal anatomy of the medusa shows a complete radial symmetry, and is simple in plan but often complicated in detail (see fig.
Oesophagus, stomach, radial canals, ring-canal and tentacle-canals, constitute together the gastrovascular system and are lined throughout by endoderm, which forms also a flat sheet of cells connecting the radial canals and ring canal together like a web; this is the so-called endoderm-lamella (e.l.), a most important feature of medusan morphology, the nature of which will be apparent when the development is described.
It appears to conform more or less to the radial or rosette type of multiplication, enlarged rounded parasites, with a varying number of nuclei (up to about eight) uniformly arranged near the periphery, having been often noticed (fig.
The agreement is too close to be dismissed as a mere coincidence, and it is confirmed by a corresponding agreement of their radial motions determined by the spectroscope; and yet, seeing that a and Ursae Majoris are 19Ã‚° apart, these two stars must be distant from each other at least one-third of the distance of each from the sun; thus the members of this singular group are separated by the ordinary stellar distances, and probably each has neighbours, not belonging to the system, which are closer to it than the other four stars of the group. Further, E.
Thus, about 1875, the distinction of Echinoderms from such radiate animals as jelly-fish and corals (see Coelentera), by their possession of a body-cavity ("coelom") distinct from the gut, was fully realized; while their severance from the worms (especially Gephyrea), with which some Echinoderms were long confused, had been necessitated by the recognition in all of a radial symmetry, impressed on the original bilateral symmetry of the larva through the growth of a special division of the coelom, known as the "hydrocoel," and giving rise to a set of water-bearing canals - the watervascular or ambulacral system.
The position of the pores near the centre of the ambulacrals in Bothriocidaris need not be regarded as primitive, since other early Palaeozoic genera, not to mention the young of living forms, show that the podia originally passed out between the plates, and were only gradually surrounded by their substance; thus the original structure of the echinoid ambulacra differed from that of the early asteroid in the position of the radial vessels and nerves, which here lie beneath the plates instead of outside them.
The important feature was the extension of radial canals from the water-sac along these grooves, with branches passing between the flooring-plates of the grooves (fig.
The radial water-vessels lie within the test through which their podia pass (fig.
The second row consists of a broad and flat magnum, supporting the great third metacarpal, having to its radial side the trapezoid, and to its ulnar side the unciform, which are both small, and articulate inferiorally with the rudimentary second and fourth metacarpals.
(X41.) in the centrifugal direction, showing l a regular radial arrangement, with medullary rays between the seri s of tracheides (fig.
Download Brochure Radial Accelerator The Radial accelerator provides an alternative to the standard push-pull hand controls.
Also related: make a transparent, hand cranked, centrifugal water pump (with purely radial impeller blades to keep explanation simple).
Keith Prime took 4th on his 640cc Rudge Special, with Robert Rushton making a welcome appearance on his fully Radial Ulster taking 5th.
I often found that power switches on radial arm saw, etc. was on and positioned for the right-handed users.
Students learn who wrote the first computer program, who discovered pulsars, who invented radial tires, science puzzles and much more !
Engine acting as swingarm, coupled to frame by two linkages mounted on radial vibration dampers.
The carpus has a radial tilt with volar subluxation.
Subsequent erosion of the chemically weathered granite took place as a generally radial drainage network evolved around the granite dome.
Stable Encoding of Robot Trajectories using Normalized Radial Basis Functions: Application to an Autonomous Wheelchair.
Select the amount you wish to pay by clicking on the proper radial button.
Cracking or radial cracking is caused by uneven watering.
The radial head is held in place by a ligament called the annular ligament.
Nursemaid's elbow is also called subluxation of the radial head, pulled elbow, slipped elbow, or toddler elbow.
Once the ligament and the radial head are returned to their proper position, the child can usually begin to use his or her arm again within a few minutes.
The radial pulse (wrist area) is detectable, but rapid.
Other techniques to correct myopia include photorefractive keratectomy (PRK), radial keratomy (RK), laser epithelial keratomileusis (LASEK), intraocular lens implants and intrastromal corneal rings.
Select a time package by clicking the radial button next to it.
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