Evolution, Racial and Habitudinal (Classic Reprint)

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Excerpt from Evolution, Racial and HabitudinalThere is, also, another character in which species Of some of these genera often di¿er from each other, in regard to which natural selec tion has never been shown to be the controlling factor. I refer to the character of the coil of the shell, which may be dextral in one species, Sinistral in another, and either dextral or Sinistral in a third. As long as it is impossible to give any reason why a species would not be equally successful if every individual possessed the reverse form from that it now has, it is unreasonable that we Should attribute the pres ent form to the in¿uence Of natural selection.The theory that there is great advantage for the species in having all the individuals coiled in the same way, if proved, would in no way explain why certain species are always dextral and certain others are always Sinistral, while some well-established species present large masses of individuals of each form. I think it will some day be shown that snails of opposite forms, though of the same race, are in capable Of mating with each other, and we already know that each individual is both male and female. If, then, an unusual sport should produce, in the same family, or on the same tree, two individuals of the reverse form from their parents, we should have a completely segregated variety established in the original home, while exposed to the same environment and using it in the same way, and its new char acter conferring no benefit.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.