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Anatomy animal Annelid anus aperture appears appendage Appendicularia arch Ascidians Asteridae attached auditory axis band becomes body bone branchial calcareous canal capsule cartilage cartilaginous cells cellular central Cephalaspis cephalic ciliated composed connected consists contained corpuscles delicate dentine described disc distinct dorsal ecderon Echinococci Echinoderm edge enamel endoplasts endostyle existence external extremity fact fibres fishes fissures ganglia ganglion genus germinal vesicle granules homologous horny inch in diameter inner integument intestine Kolliker Lacinularia lamina larva latter layer Leydig Malpighian bodies margin mass Medusa membrane Mollusca mouth muscular nerves nervous notochord nucleus observed oesophagus organs ossified otolithe outer ovum papilla parietes peculiar pedicle periplast Plate Polypes portion posterior present Prof Pteraspis pulp Pyrosoma resembling Rhizostoma Rotifera Salpa Salpce shell side sinus skull species specimens spermatozoa stomach structure structureless substance surface tentacles terminates tissue transverse tube tunic upper vascular vertebra Vertebrata vesicle vessels wall water-vascular zooid
Page 252 - Both cells and vessels may subsequently be thickened, by deposits from the " solidcscible " nutritive fluid. In the plant, the cells at first communicate, but subsequent!}' become separated from one another ; in the animal, they always remain in communication. In each case, they are mere cavities, and not independent entities ; organization is not effected by them, but they are the visible results of the action of the organizing power inherent in the living mass, or what Wolff calls the vis essentialis....
Page 277 - They are no more the producers of vital phenomena than the shells scattered in orderly lines along the sea-beach are the instruments by which the gravitation - force of the moon acts upon the ocean. Like these, the cells mark only where the vital tides have been and how they have acted.
Page 220 - Schwann consisted of two portions of very unequal value, the one anatomical, the other physiological. So far as it was based upon an ultimate analysis of living beings and was an exhaustive expression of their anatomy, so far will it take its place among the great advances in science. But its value is purely anatomical, and the attempts which have been made by its author, and by others, to base upon it some explanation of the physiological phenomena of living beings by the assumption of cell-force,...
Page 585 - It may be true to say that there is a primitive identity of structure between the spinal or vertebral column and the skull; but it is no more true that the adult skull is a modified vertebral column than it would be to affirm that the vertebral column is modified skull.
Page 192 - If, however, all Cephalous Mollusks, ie, all Cephalopoda, Gasteropoda, and Lamellibranchiata, be only modifications by excess or defect of the parts of a definite archetype, then, I think, it follows as a necessary consequence that no anamorphism takes place in this group. There is no progression from a lower to a higher type, but merely a more or less complete evolution of one type.
Page 352 - Noctiluca appear to push repeatedly against obstacles, with this tentacle. The body is composed of a structureless and somewhat dense external membrane, which is continued on to the tentacle. Beneath this is a layer of granules or rather a gelatinous membrane, through whose substance minute granules are scattered without any very definite arrangement. From hence arises a network of very delicate fibrils, whose meshes are not more than l-3000th of an inch in diameter (fig.
Page 11 - I would wish to lay particular stress upon the composition of this (the stomach) and other organs of the Medusae out of two distinct membranes, as I believe that it is one of the essential peculiarities of their structure, and that a knowledge of the fact is of great importance in investigating their homologies. I will call these two membranes as such, and independently of any modifications into particular organs,
Page 252 - In this semi-fluid mass cavities are now developed; these, if they remain round or polygonal, become the subsequent cells; if they elongate, the vessels; and the process is identically the same, whether it is examined in the vegetating point of a plant, or in the young budding organs of an animal.
Page 282 - Milne-Edwards, and Newport. Leaving out of consideration (for want of time merely) the Radiate animals, and passing to the remaining great division, the Mollusca, it appears that the same great principle holds good even for these apparently unsymmetrical and irregular creatures : and the Lecturer, after referring to the demonstration of the common plan upon which those Mollusks possessing heads are constructed, — which he had already given in the Philosophical Transactions...