1913] Grinnell-Swarth: Birds and Mammals of San Jacinto 343 



intermedia San Jacinto region desertorum 



Fig. C. Diagram showing individual and geographic variation in length 

 of hind foot of certain adult white-footed wood rats. Solid lines, males; 

 broken lines, females; figures at left and right of these lines, respectively, 

 indicate numbers of individuals measured; length of lines shows range of 

 individual variation; points connected by solid and broken lines, respec- 

 tively, mark positions of averages. Again note general reduction in the 

 dimension geographically from the San Diegan district (at left) through 

 the San Jacinto region to the desert. 



