36 BOARD OF AGRICULTURE. [Pub. Doc. 



that crossing within the variety and change of stock within 

 ordinary bounds are beneficial, that the results 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. These processes are much 

 more important than any mere groping after new varieties, 

 as I have already said ; not only because they are surer, but 

 because they are universal and necessary means of maintain- 

 ing and improving both wild and cultivated plants. Even 

 after one succeeds in securing and fixing a new variety, he 

 must employ these means to a greater or less extent to main- 

 tain fertility and vigor. In the case of some garden crops, 

 in which many seeds are produced in each fruit and in which 

 the operation of pollination is easy, actual hand-crossing 

 from new stock now and then may be found to be profitable. 

 But in most cases the operation can be left to nature, if the 

 new stock is planted among the old. Upon this point Dar- 

 win expressed himself as follows : " 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 thor- 

 ough 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 seeds." 



But you are waiting for a discussion of the second of the 

 great features of crossing, — the summary production of 

 new varieties. This is the subject which is almost univer- 

 sally associated with crossing in the popular mind, and even 

 among horticulturists themselves. It is the commonest 

 notion that the desirable characters of given parents can be 

 definitely combined in a pronounced cross or hybrid. There 

 are two or three philosophical reasons which somewhat 

 oppose this doctrine, and which we will do well to consider 

 at the outset. In the first place, nature is opposed to 



