16 



MAMMALS IX THEIR RELATION TO SPOTTED FEVER. 



HOUSE MOUSE. 



(Mas musculus.) 



House mice are common in the fields and brush as well as in and 

 around farm buildings in the valley, but none were examined for 

 licks. 



* WHITE- FOOTED :M0USE. 



The white 

 mammal of 



(Pcromijsciis vniniculatus artemisiw.) 



■footed mouse is probably the most generally distributed 

 the valley, and occurs throughout its entire length and 

 from the river well up on to the mountains. It 

 was taken in every sort of country — under fallen 

 logs, on sage-covered benches, on hot, rocky pine- 

 covered slopes, on cold, damp slopes, in houses and 

 stables, in damp meadows, and in dry fields. They 

 are strictly nocturnal, live mainly on seeds and 

 grain, and are active throughout the year. As 

 most of these mice were taken in guillotine traps, 

 any ticks which might have been on them would 

 in most cases have become detached before the mice 

 were found. One partially engorged Dermacentor 

 vemistKs nymph was, however, taken from the ear 

 of one of these mice caught in a hayfield. 



* WOOD RAT. 



(Xeotoma cinerea.) 



Wood rats, pack rats, or mountain rats occur in 

 the mountains and along both sides of the valley 

 for practically its whole length. They are to be 

 found in many cf the unoccupied cabins near the 

 foothills ; and I have seen their signs in rock slides 

 up to 7,500 feet. They are nocturnal, nonhiber- 

 nating animals of rather omnivorous food habits. 

 Green leaves, floAvers, fruit, seeds, grain, nuts, and 

 almost any cooked food from the pantry are ac- 

 ceptable to their taste. Although only one tick, 

 a nymph (genus unknown), was taken from a 

 wood rat, it is probable that under some circumstances they occa- 

 sionally harbor fever ticks in the young stages. 



[Cir. 82] 



Fig. 6. — White-footed 

 mouse (Pcromyscus 

 maniculatus arte- 

 misice). (About | 

 natural size.) 



