Journal of Morphology, 1. köideGinn & Company, 1887 |
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adult appearance arise Arthropods axis band becomes body brain canal caudal cavity cells centre Clepsine cocoon commissure compound eye cone connection constriction cord cranial flexure curve described dorsal ectoblast ectoderm edge embryo epiblast epidermis epithelium fore-brain fork formation ganglia ganglion-cells germ-bands germinal vesicle gill-clefts head head-cavity Hentz hind-brain hypoblast hypophysis inner intestine invagination larvæ larval lateral walls layer legs lobes longitudinal fibres lumen macromere median line medulla medullary fold mesoblast mid-brain mouth nasal Nephelis nephridia nerve nerve-fibres neural neuromere notochord nuclei observations ocellus ommateum ommatidia oöplasm optic stalk optic vesicle origin outer pair Petromyzon pigment pineal plane portion position posterior primary primitive pronuclei region represented retina retinophora rods rows rudiment sagittal seen Shipley shows side species spermatozoon Sphyranura spider spinal stage structure subzonal membrane surface teloblasts thalamencephalon thickening tion Transverse section ventral ventricle vertebrates vitellus yolk-sac Zool
Popular passages
Page 364 - ... bear any resemblance whatever to ours. An insect's capacity to distinguish red from blue or yellow may be (and probably is) due to perceptions of a totally distinct nature...
Page 364 - ... the centre of the web at the time that the fork is applied, it cannot tell which way to go until it has been to the centre to ascertain which radial thread is vibrating, unless of course it should happen to be on that particular thread or on a stretched supporting thread in contact with the fork. If when a spider has been enticed to the edge of the •web the fork is withdrawn and then gradually brought near, the spider is aware of its presence and of its direction, and reaches out as far as...
Page 364 - ... it has discovered a fly, all its motions are altered ; its cephalothorax, if the fly moves, turns to it, with the firm glance of an animal which can turn its head ; it follows all the motions of its prey with the watchfulness of the falcon, hurrying its steps or slackening its pace, as the case may require. Gradually, as it draws near to the unsuspecting victim, its motions become more composed, until, when very near, its movements are entirely imperceptible to the closest observation, and, indeed,...
Page 141 - The question of original basis, like that of original function, must be considered in the light of what is known about the development of the larval nephridia.
Page 364 - ... is gradually brought near a spider that has not been disturbed, but which is waiting as usual in the middle of the web, then instead of reaching out towards the fork the spider instantly drops — at the end of a thread of course.
Page 207 - XIX, fig. 10) et mieux encore dans les œufs traités par l'acide acétique glacial (pi. XIX, fig. 9). III. — Changements que subit le zoosperme pendant la seconde période de la maturation de l'œuf. Le spermatozoïde, modifié comme je l'ai exposé plus haut, occupe pendant toute la période qui se termine par l'expulsion du second globule polaire et la libération de la seconde couche périvitelline le centre géométrique de l'œuf.
Page 270 - A Contribution to the Embryography of Osseous Fishes, with special Reference to the Development of the Cod (Gadus morrhua).
Page 236 - Ganz anders aber liegt das Ding bei der Hypothese die in der zweiten meiner 'Studien, etc.,' dargelegt ward. Dieser Hypothese zufolge handelt es sich bei der Hypophysis um den letzten Rest einer ursprünglich selbständigen, vor dem Munde befindlichen Kiemenspalte. Einer solchen Deutung fügt sich die dauernd erhaltene Structur der Hypophysis in ihren Beziehungen zu den...
Page 207 - ... La position relative des deux pronucleus n'est pas constante. Au début le pronucleus mâle se trouve le plus souvent dans l'hémisphère inférieur et parfois même il est assez voisin du pôle inférieur de l'œuf. Puis les deux pronucleus se rapprochent l'un de l'autre vers le centre de l'œuf. Pour se rejoindre à son congénère le pronucleus femelle, qui prend toujours naissance au voisinage du pôle supérieur de l'œuf, parcourt un chemin beaucoup plus long que le pronucleus mâle ; celui-ci...
Page 364 - This very common spider, almost domesticated in our houses, by its habits, deserves a longer notice than others. It dwells in cracks around sashes, doors, between clapboards, etc., and may be seen on the sunny side of the house, and in the hottest places, wandering in search of prey. It moves with agility and ease, but usually with a certain leaping gait. The moment, however, it has discovered a fly, all its motions are altered ; its cephalothorax, if the fly moves, turns to it, with the firm glance...