74 SECRETS OF ANIMAL LIFE 
the ear-hole a little below and behind the eye and 
not wider than a match. And there is that curious, 
worn, warty, callous cushion near the front end of 
the snout, which goes by the name of the bonnet. 
The imagination is tickled by the sparse groups 
of hairs about the snout, jaws, and chin. They are 
probably the dwindled residue of an abundant 
primeval pellage, for some embryo cetaceans show 
numerous hair-rudiments on the anterior half of the 
body. It is possible, however, that the ancestral 
Cetaceans had, even more than hair, an armature of 
scales, which was lost when aquatic habits were 
acquired. Some porpoises still show traces of 
scales, and there are some cetaceans in which no 
vestige of hair has been found, even before birth. 
The hairs seen on the Right Whale are without 
hair-muscles or sebaceous glands, but it is appa- 
rently to some purpose that they linger, for they 
are extraordinarily well innervated, four hundred 
nerve-fibers sometimes going to a single hair! 
They illustrate the conservatism of evolutionary 
processes, holding fast that which is good, even if it 
be diverted to a new function. It may be, however, 
that tactility was the primary function of hairs; we 
see it highly developed in the whisker hairs of many 
mammals, like the cat, and less familiarly in various 
types, in strategically disposed tufts about the hands 
and feet. Very impressive are the deeply buried 
relics of a hip-girdle and thigh-bone, measuring in a 
typical specimen of a North Atlantic Right Whale 
18 and 5 inches respectively. They show an 
