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 



