152 Heredity and Eugcnies 



young they were black, but with a few red hairs among the black ones. 

 The}' bore no white hairs. 



An autopsy made an hour after the death of the mother showed on 

 the left side a distinct ovarian mass about a centimeter from the coiled 

 part of the tndduct; that is, approximately the position where the 

 graft from the pure black guinea-pig was fastened at the first operation. 

 On the right side the mesentery of the oviduct was adherent to the 

 body wall where an incision had been made at the second operation, 

 and a small amount of tissue, regarded as possibly ovarian, was there 

 observed. The tissue from the left side was found to contain numerous 

 large egg follicles, some already well advanced, containing a lymph space; 

 in addition a number of corpora hitea were observed. On the right 

 was found a small amount of undoubted ovarian tissue, with one 

 well-advanced egg follicle, but the whole apparently was strongly 

 encapsulated, so that no eggs could be discharged even if they came to 

 maturity. 



It is interesting to note that both grafts persisted, though taken 

 from different animals and transferred at different times. This result 

 suggests a possible susceptibihty on the part of the animal grafted. 



Female 1,970, a daughter of the grafted albino, was mated with 

 the albino male, her father, and bore three young, two of which were 

 albinos and one black with some red hairs. If female 1,970 had been 

 the daughter of a pure black mother, instead of a grafted albino, we 

 should have expected her to produce an eciuaUty of black and albino 

 young. The observed result was the nearest possible numerical 

 agreement with this expectation. 



A control mating of the albino male was made with a female of pure 

 black stock. As a result there were produced two litters of young, 

 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 mfluence of the grafted 

 albino, but to influence of the male parent. The young of the 

 grafted mother were exactly in color such 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 yomig forms no exception 

 to this statement. Spotting characterized the race of guinea-pigs from 



