INHERITANCE OF ACQUIRED CHARACTERS 175 



influenced that at a later time the fully fertilized egg 

 would exhibit the results of fertilization by spermatozoa 

 from two different males. The possibility of such double 

 fertilization is extremely remote. The known facts 

 regarding the successful fertilization of the egg are all 

 against such an hypothesis. The egg is probably not 

 susceptible to fertilization by the sperm except during 

 a comparatively brief period which is coextensive with 

 the heat period in the domestic animals. The immature 

 ova still structurally a part of the ovary are not in proper 

 condition to be fertilized. The probabilities are all 

 against any such influence from this source. 



Is it possible that the characters of the male may 

 become impressed upon the pregnant female through the 

 influence of the foetus ? If the body (soma) of the female 

 is influenced in this way is this influence of such a nature 

 that it can be impressed upon the embryo in the uterus ? 

 If it can, then the characters of a previous male may 

 affect the later offspring by other males. Here again we 

 must admit that the period of gestation may change the 

 body of the mother to some extent, but it is extremely 

 improbable that such change influences the offspring in 

 any hereditary sense. As Rabaud 1 says, " Gestation 

 naturally produces in the female a modification which 

 we must suppose to be to some extent permanent. As 

 a consequence, the female which produces a second off- 

 spring is no longer the female that produced the first 

 offspring; whether the two gestations be due to the 

 same male or to two different males, the foetus of the sec- 

 ond gestation evolves in conditions different from those 

 surrounding the foetus of the first gestation. But it does 



1 Etienne Rabaud, "Telegony," The Journal of Heredity, 

 vol. 5, p. 389. 



