SYSTEMS OF BREEDING 



623 



increased fertility when sub- OFFSPRING OF HERO COMPARED WITH 

 jected to self-fertilization, but ORDINARY INBRED SEEDLINGS, 



SEVENTH GENERATION OF 

 INBREEDING 



OFFSPRING OF HERO COMPARED WITH 



CROSS-FERTILIZATION SEEDLINGS, 



SEVENTH GENERATION OF 



INBREEDING 



in not profiting from a cross 

 with a distinct stock." 



Here is excellence through 

 inbreeding under what may 

 be called the hardest condi- 

 tions, and it gives great en- 

 couragement to the belief that 

 if it is necessary to secure a 

 strain of plant or animal that 

 will prosper under inbreeding, 

 that strain can be produced, 

 and that its production is a 

 question only of time, pa- 

 tience, and expense. Hero will 

 undoubtedly be called a mu- 

 tant in these days, but mutants 

 are welcome. It must be borne 

 in mind that Hero was not the 

 only individual that demon- 

 strated its superiority to cross- 

 bred plants, but that this was 

 a common circumstance 

 throughout the experiments. 



Nor was the morning-glory 

 the only case of the kind. Con- 

 cerning his experiments with Mimulus (the monkey-flower, of no 

 consequence to us except as showing a principle) he says : l 



In the third and fourth generations a tall variety, often alluded to, hav- 

 ing large white flowers blotched with crimson, appeared amongst both the 

 intercrossed and the self-fertilized plants. It prevailed in all the later self- 

 fertilized generations, to the exclusion of every other variety, and trans- 

 mitted its characters faithfully, but disappeared from the intercrossed 

 plants. . . . The self-fertilized plants belonging to this variety were not only 

 taller but more fertile than the intercrossed plants, though these latter in 

 the earlier generations were much taller and more fertile than the self- 

 fertilized plants. 



1 Darwin, Cross and Self Fertilization, etc., p. 348. (Italics are mine.) 



