A Text-book of Zoology, Volume 2

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Macmillan and Company, limited, 1921 - Zoology
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Page 661 - ... would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE endued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity-, and of delivering down those improvements by generation to its posterity, world without end!
Page 671 - Thus, whatever system of organs be studied, the comparison of their modifications in the ape series leads to one and the same result — that the structural differences which separate Man from the Gorilla and the Chimpanzee are not so great as those which separate the Gorilla from the lower apes.
Page 638 - The range of variation is so great among Foraminifera as to include not merely the differential characters which systematists proceeding upon the ordinary methods have accounted specific, but also those upon which the greater part of the genera of this group have been founded, and even in some instances those of its orders.
Page 142 - ... but usually the centra are strengthened by radiating or concentric lamella: of bone ; or they may be completely ossified." On the other hand (an inconsistency due probably to duplicate authorship and multiple responsibility) we find in the description of Chiloscyllium on p. 136, the statement that the skeleton is composed entirely of cartilage with, in certain places, depositions of calcareous salts. And, moreover, in the histological introduction in the first volume " calcified cartilage " is...
Page 547 - ... formed, and pulp-cavity widely open at base. III. Completely formed human incisor, with pulp-cavity contracted to a small aperture at the end of the root. IV. Human molar with broad crown and two roots. V. Molar of Ox, with the enamel covering the crown, deeply folded and the depressions filled with cement. The surface is worn by use, otherwise the enamel coating would be continuous at the top of the ridges. In all the figures the enamel is black, the pulp white, the dentine represented by horizontal...
Page 668 - ... stated that I attribute the modification of species exclusively to natural selection, I may be permitted to remark that in the first edition of this work, and subsequently, I placed in a most conspicuous position— namely, at the close of the Introduction — the following words: "I am convinced that natural selection has been the main but not the exclusive means of modification.
Page 661 - ... would it be too bold to imagine, that in the great length of time, since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to imagine that all warm-blooded animals have arisen from one living filament...
Page 661 - ... shall we conjecture that one and the same kind of living filament is and has been the cause of all organic life ? * ******
Page 132 - ... in the ventricles of the brain, and the central canal of the spinal cord ; and in the convoluted tubules of the kidney.
Page 667 - Are those divisions artificial or natural ? Are they the devices of the human mind to classify and arrange our knowledge in such a manner as to bring it more readily within our grasp and facilitate further investigations, or have they been instituted by the Divine Intelligence as the categories of his mode of thinking?

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