Studies in the Theory of Descent, Vol. 2 of 2 (Classic Reprint) - Softcover

Weismann, August

Softcover

ISBN 10: 1332558585 ISBN 13: 9781332558582

Verlag: Forgotten Books, 2018

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Reseña del editor:

Excerpt from Studies in the Theory of Descent, Vol. 2 of 2

If variability is to be understood as indicating the period of re-modelling of a living form, whether in its totality or only in single characters or groups of characters, from the simple fact of the hetero chronic variability of the ontogenetic stages, it fol lows that the latter can be modified individually, and that the re-modelling of one stage by no means necessarily entails that of the others. It cannot however be doubted that variability, from whatever cause it may have arisen, is in all cases competent to produce a new form. From the continued crossing of variable individuals alone, an equalization of differences must at length take place, and with this a new, although not always a widely deviating, constant form must arise.

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This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Reseña del editor:

Excerpt from Studies in the Theory of Descent, Vol. 2 of 2

It would be meaningless to assert that the two stages above mentioned were completely independent of one another. It is obvious that the amount of organic and living matter contained in the caterpillar determines the size of the butterfly, and that the quantity of organic matter in the egg must determine the size of the emergent larva. The assertion in the above heading refers only to the structure; but even for this it cannot be taken as signifying an absolute, but only a relative independence, which, however, certainly obtains in a very high degree. Although it is conceivable that every change of structure in the imago may entail a correlative change of structure in the larva, no such cases have as yet been proved; on the contrary, all facts indicate an almost complete independence of the two stages. It is quite different with cases of indirect dependence, such, for example, as are brought about by 'nurse-breeding.'

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Über diese Auflage

• Verlag: Forgotten Books
• Erscheinungsdatum: 2018
• ISBN 10: 1332558585
• ISBN 13: 9781332558582
• Einband: Tapa blanda
• Anzahl der Seiten: 370