BEGINNINGS OF THE HETEROSIS CONCEPT 17 



then transferred to the United States Department of Agriculture and did no 

 further work with corn. In Shamel's final report of his own corn experiments 

 (1905), he laid no stress on the positive gains which resulted from cross- 

 breeding, but only on the injurious effects of inbreeding. His "frame of ref- 

 erence" was the normally vigorous crossbred (open-pollinated) corn, and the 

 relation between self-fertilized and cross-fertilized corn was that of something 

 subtracted from the crossbred level, not something added to the inbred level. 

 The prime objective in a breeding program, he said, "is the prevention of the 

 injurious effects of cross-fertilization between nearly related plants or in- 

 breeding." In summing up the whole matter he said: 



In general, ... it would seem that the improvement of our crops can be most rapidly 

 effected with permanent beneficial results by following the practice of inbreeding, or cross- 

 ing, to the degree in which these methods of fertilization are found to exist naturally in the 

 kind of plant under consideration. 



This means, for corn, practically no self-fertilization at all, and makes it 

 obvious that, at least for Shamel, the heterosis concept had not yet arrived. 



Edward Murray East was associated with the corn work at the University 

 of Illinois, off and on, from 1900 to 1905. He worked mainly in the role of ana- 

 lytical chemist in connection with the breeding program of C G. Hopkins 

 and L. H. Smith. He must have been familiar with the inbreeding work of 

 Shamel, if not with that of Holden. It is generally understood that he did 

 no self-fertilizing of corn himself, until after he transferred to the Connecti- 

 cut Agricultural Experiment Station in 1905. Some of his inbred lines at 

 Connecticut may have had the inbreeding work at Illinois back of them, as 

 he secured samples of seeds of the Illinois inbreds sent to him by Dr. H. H. 

 Love, who assisted him for one year and succeeded him at Illinois. But ac- 

 cording to his subsequently published records these older inbred lines did not 

 enter to any important extent into his studies in Connecticut. 



As reported in Inbreeding and Outbreeding (East and Jones, pp. 123, 124), 

 "The original experiment began with four individual plants obtained from 

 seed of a commercial variety grown in Illinois known as Leaming Dent." 

 Table III (p. 124) presents the data for these four lines for the successive 

 years from 1905 to 1917, and clearly indicates that the selfing was first made 

 in 1905. East's work is so adequately presented in this excellent book that it 

 seems unnecessary to comment on it further here except to recall that, as 

 shown by his own specific statements, my paper on "The composition of a 

 field of maize" gave him the viewpoint that made just the difference between 

 repeated observations of heterosis and the heterosis concept. In proof of this 

 we have not only his letter to me, dated February 12, 1908, in which he says: 

 "Since studying your paper, I agree entirely with your conclusion, and won- 

 der why I have been so stupid as not to see the fact myself"; but we also 

 have the published statements of his views just before and just after the 

 publication of my paper. Thus, we read in his Conn. Agr. Exp. Sta. Bull. 158, 



