

INFLUENCE OF A PREVIOUS IMPREGNATION. 277 



the greater or less development and duration of the 

 corpus luteum^ and, although it has been supposed that 

 this difference is owing to the greater vascular activity 

 of the generative organs of the female during preg- 

 nancy, it appears probable, from the facts that have 

 been presented, that the corpus luteum of pregnancy 

 derives its distinctive peculiarities from the direct in- 

 fluence of the male element upon the ovary. 



Mr. Darwin cites a number of instances in the 

 vegetable kingdom to show the " direct action of the 

 male element on the mother-form," and he comes to 

 the conclusion that " the male element not only affects, 

 in accordance with its proper function, the germ, but 

 the surrounding tissues of the mother-plant." ' 



After citing some of the cases that have already 

 been presented of the influence upon offspring of a 

 previous impregnation of the mother, Mr. Darwin 

 says, " The analogy from the direct action of foreign 

 pollen on the ovarium and seed-coats of the mother- 

 plant strongly supports the belief that the male ele- 

 ment acts directly on the reproductive organs of the 

 female, wonderful as is this action, and not through 

 the intervention of the crossed embryo." a 



It will be observed that this explanation of the 

 continued influence of the male upon offspring by 

 another male is precisely the same as that given by 

 Agassiz, and it is believed that there is a strong pre- 

 ponderance of evidence in its favor. 



In the first observed cases, it was claimed that this 

 peculiar influence of the male was limited to the first 



1 " Animals and Plants under Domestication," vol. i., p. 483. 

 * Ibid., p. 486. 



