COAT CHARACTERS IN GUINEA-PIGS AND RABBITS. 



The result observed is in exact agreement with the expected Men- 

 delian ratio, 3:1. 



From what was said on page 24 concerning the transmission of pig- 

 ment characters by albino gametes, we should expect that the charac- 

 ter of the albino used in a cross with black would in some measure 

 influence the result of the cross. That this is actually so is indicated 

 by comparing results of matings (i) and (2), page 35, the black parent 

 being the same in both matings, but the albinos markedly different. 

 One of the albino males (cf 635) forms gametes about half of which 

 are entirely free from black ; the other (c? 2002) always transmits black 

 pigmentation, frequently with a tendency to spotting. By the former 

 were produced nine young, all but two of which were self-colored black ; 

 by the latter were produced four young, all spotted with red or black. 



THE RED TYPE. 



Red (including its dilute forms known as yellow and cream) is the 

 only one of the three pigments of the coat which I have been able to 

 obtain unquestionably free from the other two. Red and yellow ani- 

 mals not only form no black pigment in their hair, but appear to be 

 incapable of transmitting the capacity to form black coat pigment. Red 

 animals mated inter se ordinarily produce only red offspring, but reds 

 obtained by cross-breeding with black may produce yellows when bred 

 inter se. This case will receive further attention presently. Yellow 

 mated with yellow produces, in my experience, only yellow offspring. 



The relations of red to agouti and to black have already been dis- 

 cussed, and in part also that of red to albinism. Accordingly it remains 

 only to consider in greater detail the last-named topic. 



