127 



"These tests and those recorded in Bulletin No. 1.3 are 

 indicative of the same conclusion, viz. That our best varieties 

 of wheat, as Blue Stem and Scotch Fife, are quite stable as 

 to the characters which they maintain and transmit to the 

 progeny under general methods of culture " A cross is good 

 because new combinations enter. If these are desirable and 

 strongly manifested, the plant is better fitted for the battle 

 of life. 



Bailey says: "For the purposes of this discussion it is 

 enough to know that crossing within the variety and change 

 of stock within ordinary bounds are beneficial, that the re- 

 sults in the two cases seem to flow from essentially the same 

 causes, and that crossing and change of stock combined give 

 much better results than either one alone, and this benefit is 

 expressed more in increased yield and vigor than in novel 

 and striking variations." 



Darwin says on this point. "It is a common practice 

 with horticulturists to obtain seeds from another place having 

 a very different soil, so as to avoid raising plants for a long 

 succession of generations under the same conditions; but 

 with all the species which freely intercross by the aid of 

 insects or the wind, it would be an incomparably better plan 

 to. obtain seeds of the required variety, which had been raised 

 for some generations under as different conditions as possible, 

 and sow them in alternate rows with seeds matured in the old 

 garden. The two stocks would then intercross, with a 

 thorough blending of their whole organizations, and with no 

 loss of purity to the variety, and this would yield far more 

 favorable results than a mere change of seed." 



Impotency. John Scott'" observed that in a species of 

 Primula {Primula vertidlatia), although the stamens and 



10 See Hildebrand, geschlechter vertheilung bel den pfianzen, p. 68. 



