10 ON GERMINAL TRANSPLANTATION IN VERTEBRATES. 



including - five individuals, all black, but with red hairs interspersed. This 

 result shows that the red hairs found on the six young of the grafted albino 

 were due, not to foster-mother influence of the grafted albino, but to influ- 

 ence of the male parent. The young of the grafted mother were exactly 

 such in color as the black guinea-pig which furnished the graft herself 

 might have been expected to bear had she been mated with male 654 instead 

 of being sacrificed to furnish the graft. The white foot borne by one of the 

 young forms no exception to this statement. Spotting characterized the race 

 of guinea-pigs from which the father came. He was himself born in a litter 

 which contained spotted young, whereas neither the pure-bred black race 

 that furnished the graft nor the albino race that received it was character- 

 ized by spotting. 



Inasmuch as the offspring of albino parents are invariably albinos, it is 

 certain that the six pigmented offspring of the grafted female were all 

 derived from ova furnished by the introduced ovarian tissue taken from a 

 black guinea-pig. This tissue was introduced while the contained ova were 

 still quite immature, and it persisted in its new environment for nearly a 

 year before the eggs were liberated which produced the last litter of three 

 young. These young, like the earlier litters, gave no indication of foster- 

 mother influence in their coloration. 



The conclusion is forced upon us that the egg-cell during its growth does 

 not change in germinal constitution. Its growth is like the growth of a 

 parasite or of a wholly independent organism : what it takes up serves as 

 food; this is not incorporated merely in the growing organism; it is made 

 over into the same kind of living substance as composes the assimilating 



organism . 



POSTSCRIPT. 



While this paper was in press a second case, from a new series of experi- 

 ments, belonging in Group I came to light. 



An albino female, No. 2475, born on the 22d of March, 1910, at 75 days of 

 age was operated upon, being, doubly castrated and receiving the ovaries 

 from a half-sister, No. 2507, a brown-eyed cream animal, 17 days younger 

 than herself. She was then mated with an albino male, her half-brother, 

 No. 2402. On October 20, 136 days after the operation, she gave birth to 

 an albino young one. We considered this an indication that the castration 

 had been imperfect, but allowed the animal to breed again. Much to our 

 surprise, 73 days later, on January 1, 1911, she gave birth to two young, 

 one of which was a brown-eyed cream like the animal which furnished the 

 graft. The other young was an albino. 



The albino young borne by this grafted animal can not properly be 

 regarded as evidence of somatic influence on the introduced graft. For 

 albinism occurred as a recessive character in the particular brown-eyed 

 cream stock used, as is evident from the fact already stated that the colored 

 animal which furnished t' e graft and the albino which received it were 

 half-sisters. The character of the young obtained and their numerical pro- 

 portions are exactly such as the colored animal would herself have been 

 expected to give, had she not been sacrificed to furnish the grafts, but had 

 been mated with the albino male. 



