THE SCIENCE OF GENETICS 



Too New to be Accurately Delimited — Represents an Empirical Study of Problems 



Which Have Been Treated Philosophically for Centuries — Its Importance to 



Agriculture — Its Application to the Improvement of the Human Stock/ 



Arthur W. Gilbert 

 Professor of Plant Breeding, State College of Agriculture, Cornell University, 



Ithaca, N. Y. 



THE science of genetics is so new 

 that it is impossible to say at 

 present just what it comprises 

 and what its boundaries shall be. 

 Until very recently, it did not even have 

 a name, but the word "genetics", sug- 

 gested by Professor William Bateson, 

 has now been universally adopted. He 

 says this word "sufhciently indicates 

 that our labors are devoted to the 

 elucidation of the phenomena of hered- 

 ity and variation, in other words, to the 

 physiology of descent, with implied 

 bearing on the theoretical problems of 

 the evolutionist and the systematist, 

 and application to the practical prob- 

 lems of breeders, whether of animals or 

 plants." 



The science of genetics deals with 

 evolution in all of its phases, as well as 

 with the science and art of breeding. 

 It makes contact with other sciences, 

 especially biology, which lies at its 

 foundation, as well as chemistry and 

 sociology. 



I think it may be truly said that in 

 the development of the science of 

 genetics our people, as hrmian organ- 

 isms, are more vitally concerned than 

 in any other science. We look with 

 great admiration, which becomes almost 

 reverence, at the workers who are 

 applying the physical and chemical 

 sciences. But as great and wonderful 

 as their achievements are, they do not 

 necessarily concern all of the people. 



Genetics, however, takes part in the 

 life of ever>' man, woman, or child, 

 every plant or animal, in fact, every 

 living thing. All organisms are the 

 product of two forces acting together to 

 determine what that individual shall be. 



Neither acts without the other and they 

 are equally important. These are 

 environment and heredity. Whatever we 

 are or do, or whatever an animal or 

 plant becomes, these two factors are 

 constantly acting — the one, the external 

 conditions surrounding us, the other 

 the inherent constitution within us. 



HEREDITY LONG OVERLOOKED. 



Until very recently the factors which 

 have received the greatest amount of 

 study have been those of environment. 

 We have looked upon plants and animals 

 as controlled very largely by external 

 forces, and even the study of man has 

 centered around his environn.3nt, while 

 the greatest force, heredity, has been 

 largely overlooked. 



The development of the study of this 

 force has naturally been very slow, 

 because it is more intangible, more 

 subtle, more difhcult to measure and 

 determine accurately, than the more 

 visible external conditions. The former 

 cannot be measured in pounds, grams 

 or degrees. It is impossible, further- 

 more, to draw a sharp line between 

 heredity and environment and say 

 exactly where one stops and the other 

 begins. They are very closely linked 

 together. To say which is more impor- 

 tant in any organism requires very keen 

 analysis and a history of the individual 

 for many generations. 



Nevertheless, problems of heredity 

 and evolution have occupied the minds 

 of men from the beginning, although 

 any conclusions reached have been 

 largely speculative and not based di- 

 rectly or indirecth' upon experimental 

 data. "It is true that until 1858, when 



'Paper no. 44, Department of Plant Breeding, Cornell University, Ithaca, N. Y. 



235 



