MAMMALS IN THEIR RELATION TO SPOTTED FEVER. 



17 



RED-BACKED MOUSE. 



( E votom ys' ida h ornsifi. ) 



The red-backed mouse is com- 

 mon in damp mountain woods 

 and along streams well down 

 into the valley. No ticks were 

 found on the few specimens ex- 

 amined. 



* MEADOW 3I0USE. 

 {Microtus Diodcstns.) 



These large dark meadow mice 

 are common in the meadows 

 along both sides of the valley. 

 On the Densmore Ranch, 3 miles 

 Avest of Florence, they were very 

 abundant in a rocky run-down 

 hayfield used for pasturing 

 horses. Most of those taken had 

 been dead long enough for any 

 ticks which might 

 have been on them 

 to detach, but on 

 three which were 

 examined while 

 still Avarm three 

 partially en- 

 gorged nymphs 

 of Dermacentor 

 were found. The 

 natural food of 

 these mice is 

 green vegetation, 

 but they are fond 

 of seeds and 

 grain and can be 

 poisoned very 

 readily. They do 

 not hibernate and 

 can best be poi- 

 soned in winter 



Fig. 7. — Wood rat (Xeotoma cinerea) 

 (About 2 natural size.) 

 [Cir. 82] 



m 



when green food 

 is scarce. 



Fig. 8.— Red- 

 backed mouse 

 {E V 0 t 0 m p s 

 idaliocnsis). 

 (About 2 natu- 

 ral size.) 



