Download or read book Variations and Genetic Relationships of the Garter-Snakes (Classic Reprint) written by Alexander G. Ruthven and published by . This book was released on 2016-06-27 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Variations and Genetic Relationships of the Garter-Snakes Three steps are necessary to determine the genetic relationships and simplify Cope's elaborate arrangement of the group: (1) The value of the characters must be determined; (2) the geographic prob abilities must be utilized; (3) similarities and intergradations must be sought. It may seem super uous to insist upon the determination of the value of the characters used in systematic work on this group, for good characters, i. E., those which are constant within particular groups, are sought after by most systematists in forming their taxo nomic groups, but in the sense in which it is here used this rule means more than this, in that it also requires the discovery of the significance of the variations. 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."