THE LIFE OF MAMMALS 
The shrews are connected with their relatives, the moles, by 
various mole shrews, and by the large, web-footed, long-snouted 
aquatic “‘desmans” of the Pyrenees and of Russia, whose silky 
coat is so much valued by the peasants of the Volga Valley. 
BONES OF FOREARM AND 
MANUS OF MOLE. 
C, cuneiform ; ce, centrale; 
Z,lunar; m, magnum; #, 
pisiform; #, radius; 7s, 
radial sesamoid § (falci- 
form); 5s, scaphoid; ¢d, 
trapezoid; fm, trapezium ; 
U, ulna; «, unciform; 
#1’, the digits. 
The moles belong to the northern hemi- 
sphere alone, and differ from shrews in 
their greater size and wholly subter- 
ranean habits. The head is small, 
pointed, and almost continuous with the 
thick, tailless body, from which the 
limbs project very little, so that the 
animal has the shape of a round, pointed 
wedge; ears and eyes have almost 
disappeared and the sense of smell 
is mainly depended upon for such in- 
formation as the creature requires. 
The fur is soft, short, and lies equally 
well either backward or forward ; 
and the mouth has forty small, sharp 
teeth. The most striking adaptive 
change, however, has occurred in the 
fore limbs, to fit them to the work of 
digging. The breastbone, collar bones, 
and arm bones are all shortened, set for- 
ward (giving a great leverage), twisted 
outward and enormously strengthened, 
and terminate in a massive ‘‘hand,” 
whose fingers bear spadelike claws, 
supplemented by a special “‘sesamoid” bone, outside of the 
thumb, which really forms a sixth finger. The hind limbs are 
little changed. 
The mole passes its whole life underground, only occasionally 
coming out upon the surface at night. Its enormous strength 
enables it to force its way through compact soil, though it 
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