THE GRAY GOPHERS 119 
The rapidity with which the animal works 
isamazing. In his rare monograph on the fam- 
ily Merriam assures us that a pocket-gopher 
can make two hundred complete strokes with 
his teeth ina minute. Its jaws are so arranged 
that thirty-eight distinct single cuts are made 
, SOUTHERN POCKET GOPHER (GEOMYS BURSARIUS) . 
From a Painting by E. T. Seton. 
by the forward stroke of the jaw and twenty- 
eight by the backward stroke. Thus, the little 
creature’s jaws may make a grand total of 
13,200 cut a minute when in active opera- 
tion ! 
Large trees are sometimes entirely girdled 
