THE 



AMERICAN NATURALIST 



Vol. XLIX. Augud, 1915 No. 584 



THE CHROMOSOME VIEW OF HEREDITY AND 

 ITS MEANING TO PLANT BREEDERS 1 



E. M. EAST 

 Bussey Institution, Harvard. University 



Definite advice as to practical procedure must be based 

 on a firm foundation of fact if the leaders in the applied 

 science are to retain any confidence in those who lay the 

 first stones in the pure science. At the same time, if it is 

 clearly understood that science only approximates truth, 

 that so-called " established laws" are only highly prob- 

 able and never absolute, it can hardly be said to be unwise 

 if an inventory of fact is taken at any time. The hand- 

 writing on the wall is never finished ; some words are dim 

 and the erasures and omissions are many, but that is no 

 reason why one should not try to read it and to see what 

 it directs if he has translated aright. 



This preliminary justification of the title of this article 

 is made because our present stock of facts regarding 

 heredity points clearly to the chromosomes as vital parts 

 of the mechanism, and I wish to emphasize some impor- 

 tant practical deductions in case this position continues to 

 become more firmly established. 



A just and complete dissertation upon the role of the 



iThis paper is based upon two lectures delivered at Harvard UniverMty 

 in 1914. I hope that any cytologists who may have their attention called 



pages, as it is intended to be merely a general statement of a particular 



to thank Doctors O. E. White, T. H. Morgan and R. Goldsehmidt for their 



that they are nof responsible for the conclusions drawn. 



457 



