PRAIRIE-DOGS 153 
Whether the disease has been exterminated 
among these wild rodents, remains to be seen. 
The fact that the Beechey ground-squirrels 
have shown themselves receptive to the fleas 
which are peculiar to brown rats, and to the 
disease, led to observations and experiments as 
to other rodents. It is found that rock-squir- 
rels are quite readily infected, mice and 
pouched gophers less so, but wood-rats and 
prairie-dogs succumbed at once. There seems 
no reason to suppose that any rodent may not 
carry the fleas about in its fur a short time, if 
not permanently; or that any rodent is immune 
against the plague if punctured by an infected 
flea. A ray of light is shed upon this dark as- 
pect of the case by the announcement that along 
with the fleas goes a small staphylinid beetle 
which exists as a parasite on both rats and 
squirrels, and feeds ravenously on the fleas. 
Importance of the prairie-dog. But of all 
the ground-squirrels none equals the prairie- 
dog in interest or importance. 
It is a denizen of the dry plains east of 
the Rockies, while two or three other species 
inhabit the mountains, the Utah basin, and 
