

IMII.IMIAME IN GUINEA-PIGS. 



ma j bm men only 0.6 and 1.5 individuals respectively, so that their 



...a- n<>t surprising- 



outi p females, cf517 had 9 young of 4 different color 

 the maximum Dumber of classes expected being 6. 

 «pia T females, cf517 had 35 young, distributed among 6 dif- 

 ,Vnnt color classes, as expected. Summarizing the results from all 

 three kinds of mating*, we 6nd that the F 2 young of c?ol7 number 69, 

 distributed among 1 1 of the 12 expected classes of young, the missing 

 r h- l.ri.m one in which the expectation is for 0.6 of an individual, 

 lv more than an even chance for the production of such an indi- 

 vidual in the Dumber of young recorded. (See table 15.) 



I > A , , , ] ft— Young product d by red-eyed white parents mated inter se. 



A word as to the number of classes expected may not be out of place. 



The dark-eyed classes expected are 6, identical with those expected 



from the cross of race C animals with wild Cavia cutleri. (Compare 



p. I I The nui nber of classes expected among the red-eyed young is 



1 leas, namely 5, because red-eyed whites which have brown pigment 



in the an not be distinguished (except by breeding-test or post 



rom those which have black pigment in the eye, the quantity 



• present being too small, and the coat in both cases white. 



the whole the agreement between expected and observed in this 



i n nt is so good as to preclude the idea that any coupling or 



associatioD occurs among the 4 unit factors involved in the cross. 



This expe rim ent produced 4 color varieties of guinea-pig previously 



unknown to me, viz. the 4 red-eyed classes other than silver agoutis, 



which had already been obtained from the uncrossed lea race. (See 



plat.- 1. _\ and 5. The eve has a similar appearance in all the red- 



Bhowing a deep-red glow by reflected light. The silver 



■iiti variety, as already explained, differs from golden agouti in the 



if the fur. which is white in silver agouti, instead of red or 



Aden agouti. Sepia as compared with black has a more 



fad.d appearance, approaching chocolate on the sides of the body and 



belly, but always darker and unmistakably black above. Silver cinna- 



