Embryology or ontogenyD. Appleton, 1897 |
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allantois amnion Amphibia Amphioxus aorta appears Ascidian Baer Blastula blood-vessels body body-cavity Chick chorda cleavage cleavage-cells cœlom Comparative Anatomy connected cytula Darwin developed dorsal egg-cell egg-cleavage embryo entirely entoderm Epigenesis exoderm fact formation four secondary germ-layers furrow Gastræa Gastrula germ germ-area germ-disc germ-history germ-shield gill-arches gill-openings glands globular heart Heredity higher Vertebrates History of Evolution horn-plate human embryo important individual inner intestinal canal intestinal cavity intestinal germ-vesicle intestinal layer intestinal tube intestinal-fibrous layer intestinal-glandular layer kenogenetic Lamarck Lancelet latter lower mammalian Mammals medullary tube membrane Morula muscles natural naturalist notochord nutritive yelk ontogenetic Ontogeny organs original outer skin palingenetic parent-cell phylogenetic Phylogeny Plate primary germ-layers primitive intestine primitive kidneys primitive vertebral protoplasm Protozoa rudiment separates simple cell skin-fibrous layer skin-layer skin-sensory layer species sperm-cells spinal tube stage surface Theory of Descent tion vertebral column vesicle wall whole Wolff Worms yelk-sac zona pellucida
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หน้า 93 - And for the generality of men there will be found, I say, to arise, when they have duly taken in the proposition that their ancestor was ' a hairy quadruped furnished with a tail and pointed ears, probably arboreal in his habits...
หน้า 6 - This fundamental law, to which we shall recur again and again, and on the recognition of which depends the thorough understanding of the history of evolution, is briefly expressed in the proposition : that the History of the Germ is an epitome of the History of the Descent...
หน้า 196 - The two primary germ-layers, the outer or serous, and the inner or mucous layer, were first clearly distinguished, in 1817, by Pander, in the incubated Chick (p. 51). But their full significance was first thoroughly recognized by Baer, who, in his " History of Evolution " (1828), gave the name of animal layer to the outer layer, that of vegetative layer to the inner. These names are very apt, because it is the outer layer which especially (if not exclusively) gives rise to the animal organs of sensation...
หน้า 95 - ... apply to alter the forms, are also at work in Nature. He named the most effective of all the co-operating causes the Struggle for Existence. The gist of Darwin's theory, properly so called, is this simple idea : that the Struggle for Existence in Nature evolves new Species without design, just as the Will of Man produces new Varieties in Cultivation with design.
หน้า xxiii - war of culture," affecting- as it does PREFACE TO THE FIRST EDITION. XX111 the whole history of the World, and in which we may well deem it an honour to take part, no better ally than Anthropogeny can, it seems to me, be brought to the assistance of struggling truth. The history of evolution is the heavy artillery in the struggle for truth. Whole ranks of dualistic sophisms fall before the monistic philosophy, as before the chain shot of artillery, and the proud structure of the Koman hierarchy,...
หน้า 443 - This now undergoes a regular and total cleavage, the details of which ^na coral (Monoxenid) we have described in detail (cf. Fig. 22). The repeated bisection of the parent-cell into 2, 4, 8, 16, 32, 64 cells and so on, gives rise to the globular, blackberry or mulberry-shaped body which we called the " mulberry-germ" (morula, Fig. 22, E). Fluid collects in the interior of this globular mass, composed entirely of one sort of cleavage-cells, and the result is the formation of a spherical vesicle, the...
หน้า 60 - ... in all the tissues, and that they form the actual building material of organisms. All the numerous tissues of the animal body, such as the •entirely dissimilar tissues of the nerves, muscles, bones, outer skin, mucous skin, and of other similar parts, are originally composed of cells; and the same is true of all the various tissues of the vegetable body. These cells, which we shall hereafter consider more closely, are independent living beings, the citizens of the state, which constitute the...
หน้า 21 - It will, therefore, be the task of a future physiogeny to grasp the history of the evolution of the functions with the same earnestness, and with the same success, with which morphogeny has long ago undertaken the study of the history of the evolution of forms. A few instances will show how closely the two are connected. The heart of the human embryo has at first a very simple structure, such as appears permanently only in ascidians and other inferior worms, and connected with it is a circulation...
หน้า 1 - The History of the Evolution of Organisms consists of two kindred and closely connected parts : Ontogeny, which is the history of the evolution of individual organisms, and Phylogeny, which is the historyof the evolution of organic tribes. Ontogeny is a brief and rapid recapitulation of Phylogeny, dependent on the physiological functions of Heredity (reproduotion) and Adaptation (nutrition).
หน้า 7 - ... the series of forms through which the individual organism passes during its progress from the egg cell to its fully developed state, is a brief, compressed reproduction of the long series of forms through which the animal ancestors of that organism (or the ancestral forms of its species) have passed from the earliest periods of so-called organic creation down to the present time.