32 Department of Experimental Plant-Breeding. 



Investigation of the cumulative action of selection. 



Since the publication of Darwin's classical works, it has been be- 

 lieved that a continuous selection, generation after generation, of the 

 individuals exhibiting a character in the greatest degree, would lead 

 to a gradual augmentation of the character or characters concerned. 

 The policy of the continuous selection of the best has become one of 

 the principles of breeding, universally accepted. The investigations 

 of De Vries on mutations have thrown grave doubt on this principle 

 as the indication from his work is to the effect that the first selection 

 of a striking mutation or sport is the all-important matter, and that 

 followinp; this iirst selection all that remains to be done is to weed out 

 the effect of crossing and test the comparative value of the new strain 

 by tests with standard sorts. The continuous selection year after year, 

 entails a tremendous amount of careful, painstaking labor on the part 

 of the breeder and if nothing is accomplished by it after the first selec- 

 tion the methods should be changed. This problem, therefore, is one 

 that demands careful investigation, and experiments of this nature 

 have been started, using several varieties of wheat. Here, pure line- 

 breeding is being used, the selections in each case being taken from 

 progeny grown from the same head or spike. The investigation will 

 require to be continued many years to get conclusive evidence ; and 

 every effort will be made to make the experiments conclusive and 

 valuable. 



Studies on the influence of environment in species and variety formation. 



The effect of environment on the evolution of species is still an 

 unsettled question, demanding attention. We need to know from the 

 breeding standpoint, how such changes effect the stability of varieties 

 and species, and whether varieties of a certain type may be better 

 bred under certain environments than under others. This problem is 

 being studied as much as time will permit directly in connection with 

 the investigation of variations. Certain features connected with the 

 problem, such as the possible inhei;itance of so-called acquired char- 

 acters, are of special importance and are also receiving some attention. 



Extension Work. 



The extension work of this department is expected to be limited. 

 It is necessary, however, that experimenters keep in close touch with 

 the requirements of the State, so that a limited amount of this work 

 can be done without interruption to the experimental work and cer- 



