PREFACE 



THE following pages had their origin in a course 

 of lectures upon Heredity, given at Brown Univer- 

 sity during the winter of 1911-1912, which were 

 amplified and repeated in part the following sum- 

 mer at Cold Spring Harbor, Long Island, before the 

 biological summer school of the Brooklyn Institute 

 of Arts and Sciences. 



An attempt has been made to summarize for the 

 intelligent, but uninitiated, reader some of the more 

 recent phases of the questions of heredity which 

 are at present agitating the biological world. It is 

 hoped that this summary will not only be of interest 

 to the general reader, but that it will also be of serv- 

 ice in college courses dealing with evolution and 

 heredity. 



The subject of heredity concerns every one, but 

 many of those who wish to become better informed 

 regarding it are either too busily engaged or lack the 

 opportunity to study the matter out for themselves. 

 The recent literature in this field is already very 

 large, with every indication that much more is about 

 to follow, which is a further discouragement to non- 

 technical readers. 



It may not be a thankless task, therefore, out of 

 the jargon of many tongues to raise a single voice 



