234 University of California Fublications in Zoologij. [Vol. 7 



Tabulation of Breeding Data of Males of Feromyscus manicululus 



sonoriensis From Humboldt County, Nevada. 

 Explanation. — All the males here listed have the genital organs highly- 

 developed, indicating sexual activity. They were all marked ' ' testes large 

 in the field by the collector. Males at Quinn River Crossing did not appear 

 to be breeding in numbers during the latter part of May and the first of 

 June. The great majority of the sexually active animals are young adults 

 or old juvenals. Some are still in the adolescent pelage. Few have assumed 

 the buffy-ochracpous clay-colored pelage of the older adults. 



Museum 



Xo. Locality 



8004 Quinn River Crossing 



8006 Quinn River Crossing 



8021 Head of Big Creek, Pine Forest Mts. 



8019 Head of Big Creek, Pine Forest Mts. 



8017 Head of Big Creek, Pine Forest Mts. 



8030 Head of Big Creek, Pine Forest Mts. 

 8033 Head of Big Creek, Pine Forest Mts. 



8031 Head of Big Creek, Pine Forest Mts. 

 8029 Head of Big Creek, Pine Forest Mts. 



8043 Head of Big Creek, Pine Forest Mts. 



8044 Head of Big Creek, Pine Forest Mts. 

 8046 Head of Big Creek, Pine Forest Mts. 

 8041 Head of Big Creek, Pine Forest Mts. 

 8049 Head of Big Creek, Pine Forest Mts. 

 8048 Head of Big Creek, Pine Forest Mts. 



8054 Head of Big Creek, Pine Forest Mts. 



8052 Head of Big Creek, Pine Forest Mts. 



8053 Head of Big Creek, Pine Forest Mts. 

 8051 Head of Big Creek, Pine Forest Mts. 

 8056 Head of Big Creek, Pine Forest Mts. 



8055 Head of Big Creek, Pine Forest Mts. 



8060 Head of Big Creek, Pine Forest Mts. 



8061 Head of Big Creek, Pine Forest Mts. 



8067 Big Creek, Pine Forest Mts. 



8068 Big Creek, Pine Forest Mts. 

 8070 Meadow, Big Creek, Pine Forest Mts. 

 8073 Duffer Peak, Pine Forest Mts. 



8075 Duffer Peak, Pine Forest Mts. 



8076 Alder Creek, Pine Forest Mts. 



8077 Alder Creek, Pine Forest Mts. 

 8091 Head of Big Creek, Pine Forest Mts. 



8103 Leonard Creek, Pine Forest Mts. 



8104 Leonard Creek, Pine Forest Mts. 



8105 Leonard Creek, Pine Forest Mts. 

 8108 Leonard Creek, Pine Forest Mts. 



