QfHUUl kN( B in GUINEA-PIGS. 



HYBRIDIZATION EXPERIMENTS WITH A RACE OF FERAL 

 GUINEA PIGS FROM ICA, PERU. 



ORIGIN AND CHARACTERISTICS OF THE ICA RACE. 



Von Tschudi in 184 L, in bis Fauna of Peru, described, under the name 



B wild cavy found occurring in great numbers in the 



II, Bays thai the natives call it "cuy del monte," the 



. v. and regard it as the original of C.cobaye, the guinea-pig. 



Subeequenl writers carefully distinguish the C. cutleri of Von Tschudi 



from thai of Bennett, with which my wild cavies from Arequipa agree. 



the objects which I hoped to accomplish by the trip to Peru was 



to Irani more aboul the cavy which Von Tschudi reported as occur- 



ringal lea, and, if possible, to determine its relation to C.etriUri Bennett 



and to the guinea-pin. 



Through the kindly interesl of Messrs. W. R. Grace & Co. I was 

 able I ire 3 wild-caughl cavies (a male and 2 females) from lea 



; to bring them back with me to the Bussey Institution, where they 

 • ■ produced a numerous progeny. 



animals were about the Bize of domesticated guinea-pigs, were 

 very timid, and were -elf-colored golden agouti, in every respect similar 

 in appearance to tame guinea-pigs of the color variety named. 



animals brought from lea produced 7 golden-agouti young, 



all similar to the parents in color, except that one bore a spot of red, 



firsl observed indication of contamination of the stock with char- 



found in domesticated guinea-pigs. That other indications 



re no1 observed in this first mating of the animals was probably due 



to the fact thai the male was homozygous for all other color factors, as 



subsequent matings of the females with a son of one of them by the 



original male proved thai both mother and son were heterozygous in 



that variation of the color factor which is seen in "red-eyed" guinea- 



pi- I istle, 191 1: Wright, 1915). The same matings with the son 



ible 12 proved that one of the two original females (9 503) 



tlso heterozygous in the agouti factor and transmitted white- 



otting, since she produced a black daughter which had one white foot. 



Three other inbred descendants of the original trio of lea animals have 



if white; two of them in addition bore spots of red, 



tricolors. One of the original trio of animals from lea 



when mated with '.">n:>, produced a son (c?575) which was 



tly rough-coated. Accordingly we have clear evidence that 



the stock derived from [ca was contaminated with at least 5 of the 



ily independent unit-factor variations which occur among 



doi d guinea-pigs and there can belittle doubt that it really has 



1 wholly or in part from domesticated guinea-pig ancestors. 



