48 Observations on the Sex of Mice. [Dec. 1 



6. f (ancestry lost, about 2 months old). 



<?. ?. 



By C 1 - 3 May 20/03 6 2 



7. rj (bought May 1, 1903, at least 4 months). 







c?. 



? 



"Rtt PI »3 



June 22/03 



6 



i 

 i 



B 2 



May 30/03 



4 



4 



A 





- 1 June 24/03 



3 



4: 





June 29/03 



5 



2 





July 8/03 



4 



2 



53 11 ■•■ 



July 17/03 



6 



o 



B 2 ' 2 



July 27/03 



5 



2 







33 



17 



8. ( 



9 (C 2 + a, born August 22, 1902). 









<?• 



?• 



By ±> d ... 



Nov. 13/02 



2 



3 



T) 1 



Nov. 18/02 



5 



«_> 







7 



6 



9. i 



(C 2 + a, born August 22, 1902). 









<?. 



?• 



Bv n 2 



Dec. 20/02 



3 





C 2 



Feb. 4/03 



3 



3 



„ D 2 ... 



Dec. 21/02 



3 



3 



„ B 3 - 2 



Oct. 30/02 



6 



4 



„ D 3 - 3 



Oct. 28/02 



2 



2 



„ a.... 



May 22/03 



1 



2 







18 



17 



10. 



k (C 2 + t, born March 1, 



1903). 









&• 



¥•■ 



By C 2 .... 



May 20/03 







3 



