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Excerpt from Memorial Pamphlet Containing Certain Drawings of Medusae Numerous short, chitmous spines are developed upon the crust which covers the fibers, and thus we find the polypites arising from a flat, spinous base which adheres to the surface on which the colony is growing. The colony is composed of two kinds of hydranths: sterile feeding-polypites, and reproductive gonostyles. The sterile teedingpolypites are spindle-shaped, being abo...

Excerpt from Journal of Experimental Zoology, 1928, Vol. 15 Boveri ('02, '05) found that the size of the nuclei of the cells of sea urchin larvae is directly proportional to 'the number of chromosomes-which enter them, and that cells which contain small nuclei are below the normal size, because such cells divide more frequently than those with large nuclei. In a number of publications, the earliest of which appeared in 1890, Minot advanced t...

Excerpt from Handbook of Invertebrate Zoology: For Laboratories and Seaside Work This book is a handbook, not a text-book, and the entire absence of generalizations and comparison is not due to indifference to the generalization of modern philosophical morphology, but rather to a wish to aid beginners to study them. Most lecturers upon natural science find, no doubt, that preliminary work, the presentation of the facts upon which science is ...

Excerpt from The Foundations of Zoology a Course of Lectures IN this course of lectures I shall give, on many questions, the Scotch verdict of not proven, and experience warns us that this will be interpreted as an assertion that they are proved or disproved, although no one can, in justice, interpret an admission that a thesis may some time be proved or disproved as belief that either of these things will come about, or as an admission of an...

Excerpt from Journal of Experimental Zoology, 1904, Vol. 2 The second paper of this series dealt with variation and inherit ance Of size in Paramecium during reproduction by fission. The present paper is an experimental and Observational study Of the size relations in conjugation. A later contribution will deal with the relation of conjugation to vitality and reproduction. About the Publisher Forgotten Books publishes hundreds of thousands ...

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Excerpt from On Turritopsis Nutricula (McCrady) The primitive ova grow by the absorption of the ovarian cells around them. As growth takes place there is a change in the character of the cytoplasm. It loses its homogeneous and finely granular nature and develops a supply of deuteroplasm in the form of yolk granules. These are large and stain very darkly. They first appear around the germinal vesicle. As they become more numerous by the contin...

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Excerpt from The Embryology and Metamorphosis of the Macroura No great group of animals is more favorable than the Crustacea for the study of the history and significance and origin of larval forms, for these animals possess a number of peculiarities which serve to render the problem of their life history both unusually interesting and significant, and at the same time unusually intelligible, nor are these peculiar features exhibited, to the ...

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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work.This w...