PRAIRIE-DOGS 161 
courage to dig the owner out of their tortuous 
depth. In the West are other similar species; 
and all the high mountains from the Rockies 
westward, and far to the North, have a larger 
one which dwells near timber-line, and is known 
as the siffeur (whistler) on account of its clear 
sharp call. The food of all these marmots con- 
sists of herbage and succulent roots, and they 
do great damage in gardens where not re- 
strained. They do not store any of this food, 
however, but in the early autumn retire to their 
burrows, very fat, and pass the winter in a 
state of complete torpor, during the continu- 
ance of which their fatness decreases, being ab- 
sorbed to sustain the trifling exertion of life 
caused by the continued slow beating of the 
heart. When, therefore, they emerge early in 
the spring, they are lean and very weak, but 
soon recuperate on the fresh grass and herbage. 
Their fur is of little value, and their flesh poor, 
so that as game they are attractive only to the 
boy and his dog, or, in the West, to hungry In- 
dians. 
Food-value of the porcupine. Here, if any- 
where, should be said a few words about the 
