Unlike the giraffe, the length of the limbs is due to the elongation of their upper segments, and that of the neck to the lengthening of only the hinder vertebrae.
This order can be traced with certainty back to the early Jurassic epoch, while the Permian fossil Eugereon, and the living order - specially modified in many respects - of the Thysanoptera indicate steps by which the aberrant suctorial and piercing mouth of the Hemiptera may have been developed from the biting mouth of primitive Isopteroids, by the elongation of some parts and the suppression of others.
In., with an elongation of at least 5 per cent.), the separate wires being first covered with a firm coating of tape and Chatterton's compound (a FIG.
Medusae, so-called " meconidia," are budded but not liberated; each in turn, when it reaches sexual maturity, is protruded from the gonotheca by elongation of the stalk, and sets free the embryos, after which it withers and is replaced by another (Allman , p. 57, fig.
In other cases this growing-point becomes active at once, there being little or no elongation of the hypocotyl and tbe cotyledon or cotyledons remaining in the seed.
It may be due to insufficient illumination (Etiolation), as seen in geraniums kept in too shaded a situation, and is then accompanied by soft tissues, elongation of internodes, leaves usually reduced in size, &c. The laying of wheat is a particular case.
The formation of the conducting tubes or secretory sacs which occur in all parts of the higher plants is due either to the elongation of single cells or to the fusion of cells together in rows by the absorption of the cell-walls separating them.
Tubes formed by the elongation of single cells are found in bast fibres, tracheides, and especially in laticiferous cells.
- The Rhynchophora are a group of beetles easily recognized by the elongation of the head into a beak or snout, which carries the feelers at its sides and the jaws at its tip. The third tarsal segment is broad and bi-lobed, and the fourth is so small that the feet seem to be only four-segmented.
Later followed the appearance of lights; quasi-human voices; musical sounds, produced, it is said, without instruments; the "materialization" or presence in material form of what seemed to be human hands and faces, and ultimately of complete figures, alleged to be not those of any person present, and sometimes claimed by witnesses as deceased relatives; "psychography," or "direct writing and drawing," asserted to be done without human intervention; "spirit-photography," or the appearance on photographic plates of human and other forms when no counterpart was visible before the camera to any but specially endowed seers; 3 unfastening of cords and bonds; elongation of the medium's body; handling of red-hot coals; and the apparent passage of solids through solids without disintegration.
In place of the six stamens we commonly find but one (two in Cypripedium), and that one is raised together with the stigmatic surfaces on an elongation of the floral axis known as the "column."
This may consist simply in attaching one end of the wire to an index lever and the other to a fixed support, or the elongation of the wire may cause a rotation in a mirror from which a ray of light is reflected, and the movement of this ray over a scale will then provide the necessary means of indication.
To render the elongation evident, another wire is attached to its centre S2, this last having a thread fixed to its middle of which the other end is twisted round the shaft of an index needle or in some way connected to it through a multiplying gear.
The Angora rabbit is characterized by the extreme elongation and fineness of the fur, which in good specimens reaches 6 or 7 in.
ELONGATION, strictly "lengthening"; in astronomy, the apparent angular distance of a heavenly body from its centre of motion, as seen from the earth; designating especially the angular distance of the planet Mercury or Venus from the sun, or the apparent angle between a satellite and its primary.
The greatest elongation of Venus is about 45°; that of Mercury generally ranges between 18° and 27°.
According to Joule's observations, the length of a bar of iron or soft steel was increased by magnetization, the elongation being proportional up to a certain point to the square of the intensity of magnetization; but when the " saturation point " was approached the elongation was less than this law would require, and a stage was finally reached at which further increase of the magnetizing force produced little or no effect upon the length.
The elongation is generally found to reach a maximum under a magnetizing force of 50 to 120 units, and to vanish under a force of 200 to 400, retraction occurring when still higher forces are applied.
Merely has the effect of diminishing the maximum elongation and hastening the contraction; with the two greatest loads used in the experiment there was indeed no preliminary extension at all.'
Knott on magnetic twist, which will be referred to later, led him to form the conclusion that in an iron wire carrying an electric current the magnetic elongation would be increased.
The effect produced by a current is exactly opposite to that of tension, raising the elongation curve instead of depressing it.
In diameter the maximum elongation was nearly doubled when a current of two amperes was passing through the iron, while the " critical value " of the field was increased from 130 to 200.
Some experiments were next undertaken with the view of ascertaining how far magnetic changes of length in iron were dependent upon the hardness of the metal, and the unexpected result was arrived at that softening produces the same effect as tensile stress; it depresses the elongation curve, diminishing the maximum extension, and reducing the " critical value " of the magnetizing force.
The experiments were not sufficiently numerous to indicate whether, as is possible, there is a critical degree of hardness for which the height of the elongation curve is a maximum.
The complicated hysteresis effects which attend magnetic elongation and retraction have been studied by H.
Sample containing 25% of nickel no appreciable change was detected; others containing larger percentages, and tested in fields up to 2000, all exhibited elongation, which tended to an asymptotic value as the field was increased.
Bidwell's results for iron and nickel were confirmed, and it was further shown that the elongation of nickel-steel was very greatly diminished by tension; when 2 Joule believed that the volume was unchanged.
Austin, who found continuous elongation with increasing fields, the curves obtained bearing some resemblance to curves of magnetization.
Opisthosoma without post-anal scierite and posterior caudal elongation: with frequently a pair of small lobate FIG.
Division of the nucleolus by elongation, construction, and equilateral division of the nucleus.
Hence 1000Ã† is the elongation in millimetres per metre length per kilo.
Column 3 shows the charge causing a permanent elongation of 0.05 mm.
The tail is cylindrical, with some bushy elongation of the hairs near the end, but not forming a distinct tuft.
Three types of columns are employed: (I) the elongation is simply a straight or bulb tube; (2) the column, properly termed a "dephlegmator," is so constructed that the vapours have to traverse a column of previously condensed vapour; (3) the column is encircled by a jacket through which a liquid circulates at the same temperature as the boiling-point of the most volatile component.
Scelidotherium is another genus of large South American Pleistocene ground-sloths, characterized, among other features, by the elongation and slenderness of the skull, which thus makes a decided approximation to the anteater type, although retaining the full series of cheek-teeth, which were, of course, essential to an herbivorous animal.
In., and 22% elongation in 5 ft.
In the direction of rolling, and an ultimate elongation of 8 or io% in 8 in.
In., and the elongation 3% in 8 in.
In., and an elongation of 32 to 24% in 8 in.
And an elongation of 25%.
In very many cases the pollen is carried to the stigma by elongation, curvature or some other movement of the filament, the style or stigma, or corolla or some other part of the flower, or by correlated movements of two or more parts.
They resemble the latter in the elongation of the body, the large number of vertebrae (240 in Gymnotus), and the absence of pelvic fins; but they differ in all the more important characters of internal structure.
Un like the molluscs and annelids, however, the cloacal invagination lies outside this region, and the foot is formed by an elongation of the end of the body between the two apertures.
Barbatus (=longirostris) of Borneo is a very distinct member of this group, distinguished by the great elongation of the skull, and the presence of a tuft of long hair near the muzzle.
They may be distinguished from the Neuroptera by the elongation of the head into a beak, the small prothorax, the narrow, elongate wings with predominantly longitudinal neuration, the presence of abdominal cerci and the cruciform larva.
Australia is the home of the group of jumping species, known as jerboa-rats, characterized by the elongation of the hind limbs, arranged under the genera Notomys, Dipodillus, Ammomys and Conilurus, distinguished from one another by the structure of the molars and the number of teats and foot-pads, the second being further characterized by its long ears.
In., with an elongation of at least 20% in 8 in.
They show an elongation of forms and an excess of decoration in which the florid qualities predominate.
The aim of germination is the fixing of the embryo in the soil, effected usually by means of the root, which is the first part of the embryo to appear, in preparation for the elongation of the epicotyledonary portion of the shoot, and there is infinite variety in the details of the process.
In Asymmetron the caudal region is remarkable for the curious elongation of the notochord, which is produced far beyond the last of the myotomes.
Ebenezer Kinnersley (1711-1778) of Philadelphia made useful observations on the elongation and fusion of iron wires by electrical discharges (Phil.
The name tarsier refers to the great elongation of two of the bones of the tarsus, or ankle, and spectrum to the huge goggle-like eyes and attenuated form which constitute two of the most distinctive features of this weird little creature.
The genus agrees with Dorcopsis in the direction of the hair on the neck, but the muzzle is only partially hairy, and the elongation of the penultimate premolar is less.
- Whatever the shape and size of the individual cell, cell-filament or cell-colony, the immediate visible results of active nutrition are elongation of the cell and its division into two equal halves, t;o?.
In the first case the separated A cells assume the character of the parent cell whose division a $ °° ° gave rise to them; in the second case they o se form filaments, or, if the further elongation and divisions of the cells proceed in different directions, plates or spheroidal or other shaped colonies.
The growth of an ordinary bacterium consists in uniform elongation of the rodlet until its length is doubled, followed by division by a median septum, then by the simul- Measure- taneous doubling in length of each daughter cell, again ment of followed by the median division, and soon (figs.
If the cells remain connected the resulting filament repeats these processes of elongation and subsequent division uniformly so long as the conditions are maintained, and very accurate measurements have been obtained on such a form, e.g.
With the elongation of the body, the dorsal shield begins to project posteriorly as a shell-fold, which may increase in size to envelop more or less of the body or may disappear altogether.
The Fata Morgana, frequently seen in the Straits of Messina, consists of an apparent vertical elongation of an object situated on the opposite shore.
An elongation of the shelf to the south joins Tasmania with the mainland.