Plant-breeding Author:Liberty Hyde Bailey Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: attention to the subtleties of this Neo-Darwinian philosophy. Weismann teaches that " acquired characters," or those variations which first appear in the life... more »time of the individual because of the influences of environment, are lost, because they have not yet affected the reproductive substance. But if these characters are induced by the effect of impinging environment during two or more generations, they may come to be so persistent that the plant cannot throw them off, and they become, thereby, a part of the hereditary and non-negotiable property of the species. Now, it is apparent that in one or another of the generations which are thus acted upon by the environment, there must be a beginning towards the fixing or hereditable permanency of the new form, and we might as well assume that this beginning takes place in the first generation as in the last, since there can be no proof that it does not take place in either one. The tendency towards fixity, if it exists at all, undoubtedly originates at the very time that the variation itself originates, and it is only sophistry to assume that the form appears at one time and the tendency towards permanence at another time. Since plants fit themselves into their circumstances by means of adaptive variations, we must conclude that all adaptive variations have the power of persisting, upon occasion. NATAL AND POST-NATAL VARIATION. 15 All these remarks, whilst somewhat abstruse, have a most important bearing upon the philosophy of the origin of garden varieties, because they show, first, that changes in the conditions in which plants grow introduce modifications in the plants themselves, and second, that wherever any modification occurs it is probable that it may be fixed and perpetuated. It is necessary, at this point, that we...« less