340 JAMES ROLLIN SLONAKER 
is sufficient to allow two individuals to pass each other. He con- 
siders this one of the main thoroughfares which lead from one 
feeding ground to another. 
The method of making the burrow is described by Wood (’10) 
as follows: ‘“The burrows of the mole are always excavated, not by 
bringing dirt to the surface but by pushing it aside.” This is 
quite different from the method used by most burrowing animals. 
The head is lowered and retracted—the flexibility of the neck per- 
mitting this—the fore paws are thrust forward in front of the nostrils, 
and by a sort of swimming motion the earth is pushed aside, the head 
at the same time being advanced and raised. The flexible snout is 
kept in continual motion probably for exploring rather than for loosen- 
ing the soil, as was once thought. 
Cuvier (1817) seems to be responsible for this idea, for he 
says that the nose is armed with a peculiar bone to assist in 
digging. It is now generally conceded that Cuvier was wrong in 
his interpretation. 
The apparent ease with which the mole makes its burrows 
can be gathered from Herrick’s description of this process (’92). 
The mole may be almost said to swim through the earth, its feet not 
being beneath the body, but on either side, and so armed with broad 
spade-like claws, and so highly provided with muscles as to glide 
rapidly through the soft earth. During the passage through the earth, 
the back and shoulders wedge the earth upward, so that the course of 
the animal can be followed by the observer above. During its passage 
the highly sensitive and vibratile snout is constantly in motion, search- + 
ing for such insects, worms, etc., as may come in its way. It seems 
hardly likely that this organ really assists materially in loosening or 
removing the soil, as some have thought. 
This is also emphasized by Carpenter (’57): 
The form of the anterior limbs, and the powerful muscles with 
which they are furnished, enable the animal, not merely to dig through 
the soil, cutting through the roots, ete., which may traverse it, but 
also to throw backwards with great energy the earth which has been 
removed at each stroke. The hind limbs are small, and the feet feeble, 
in comparison with the anterior; but they serve to enable the animal 
to run through its galleries with great rapidity. 
Though the mole appears to make its burrows with compara- 
tive ease, the amount of force required must be very great. In 
