100 



ANNALS NEW YORK ACADEMY OF SCIENCES 



Crosses between the Black Spotted Waltzer and Mice with 



Chocolate Coat 



In a litter of mice from a chocolate female and a male black and white 

 waltzer, there were present young mice that are described in my notes as 

 gray. At that time, I was perfectly familiar with the different coat colors 

 of mice, yet I did not hesitate to describe the color as gray, although 

 aware that gray could not, theoretically, arise in this way. As the mice 



Fig. i 





Fig. 2 



Crosses between Black-spotted Waltzer and Chocolate-colored Mice. 



grew older, they became spotted with black (like the mice of Plate VII, 

 figs. 3, 4), and later entirely black. I thought therefore that I had prob- 

 ably made a mistake in my determination of the color of the young mice, 

 but such mice have later appeared not infrequently in the offspring of such 

 crosses (see Text-figures 1 and 2), and a study of their hair has shown that 

 there are some grounds at least for confusing their color with gray. The 



