RESULTS OF HYBRIDIZING RING-DOVES, INCLUDING 

 SEX-LINKED INHERITANCE. 



BY R. M. STRONG. 



I. INTRODUCTION. 



The work which is described in this paper was undertaken 

 at the suggestion of the late Professor Whitman. It was begun in 

 a small way during the spring of 1904 and it was continued during 

 the years from 1905 to 1909 with the hope that opportunities 

 for more extensive breeding experiments might appear later. 

 During the year 1910 it was decided to discontinue the work 

 because there was still no prospect in sight of a suitable plant 

 for the breeding of birds on a scale sufficiently large for over- 

 coming difficulties which appeared in the course of the work 

 and which will be noted in this paper. 



Two preliminary statements concerning this work have been 

 published (Strong, 'n and '12). 



Some statements concerning the care of the birds employed 

 and their breeding habits have been included with the hope that 

 they may be of value to other breeders of birds. 



Professor Whitman housed portions or all of the stock during 

 several winters, and invaluable suggestions were received from 

 him concerning the care of the doves and methods of book- 

 keeping. He also furnished some of the stock which was difficult 

 to obtain in the market. 



Because of limited cage space Professor Whitman never tried 

 to breed for statistical results. When the newly discovered 

 Mendel's law came into prominence, it naturally received 

 considerable attention from him. Though always critical of 

 Mendelianism, he nevertheless admitted that he had observed 

 phenomena which, at one time, before Mendel's law came to 

 the attention of biologists, seemed to suggest conclusions similar 

 to those of Mendel. However, the apparent absence of character 

 segregations, usually, in the numerous crosses between species 



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