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.
That is to say, in a radial direction from, or (in the manubrium) parallel to, the same ideal axis.
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.
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.
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).
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.
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.?"
Buds may be produced from the manubrium, radial canals, ring-canal, or tentaclebases, or from an aboral stolon (Narcomedusae).
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.
- 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.
- 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.
Amphogona, hermaphrodite, with male and female gonads on alternating radial canals.
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.
The radial canals may be simple or branched, primarily four, rarely six in number.
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.
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.
In some Leptomedusae the gonads are formed on the radial canals and form protruding masses resembling sporosacs superficially, but not in structure.
E, Transverse sec- r.c. Radial canal.
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.
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.