170 Inheritance of Coat Colour in Mice 



Both 1667 (/"and 1555 % were agoutis and not to be distinguished 

 in any way externally from any ordinary agouti. 



I mated the yellow agouti mouse (1825 ^) with 6 does, but unfor- 

 tunately the matings were not all successful. With a chocolate % 

 there were 20 young (not one of which was agouti), 1 yellow, 4 blacks, 

 7 sables, 1 chocolate yellow belly, 3 chocolates, 3 albinos, 1 chocolate- 

 lilac. 



Mated with a yellow mouse carrying chocolate he gave 2 yellows, 

 2 sables, 3 blacks and 1 chocolate. 



I tried him four times with agouti mice but in each case there was 

 no result. I had hoped by such matings to obtain agoutis which would 

 throw yellows or sables. 



None of the offspring mated together produced any agoutis. 



Case II. A champagne % was mated with an agouti ^. In the 

 first generation there were 



1 agouti, 4 cinnamon agouti, 1 chocolate. 



The agouti which was a (/ was mated with the only % a cinnamon 

 agouti, and there resulted 



1 sooty yellow, 2 silver cinnamon agouti and 1 black. 



Unfortunately death carried off the yellow before she could be 

 mated. Subsequent litters of the parents did not contain any yellows. 



In the subjoined tables the calculations are made on a 2 to 1 basis 

 instead of the ordinary 3 to 1, adopting the conclusion indicated above. 



TABLE OF RESULTS. 



Dark-eyed Yellows. 



Yellows carrying chocolate mated together : 



Yellow Chocolate 



136 68 observed 



136 68 calculated 



Yellows carrying chocolate x chocolate : 



Yellow Chocolate 



66 46 observed 



56 56 calculated 



Yellows carrying black and chocolate mated together : 

 Yellow Black Chocolate 



65 35 9 observed 



72 27 9 calculated 



