182 ALLEN: NEW ENGLAND WHALEBONE WHALES. 



fourth furrow of that side. In one individual only there was an irregular pure white blotch 

 on the right side of the dorsal fin near its tip. True noted in some individuals a darker gray 

 band passing from above the eye upward and backward on to the shoulder. "There is commonly 

 a light gray, or whitish, mark under the eye, especially on the right side, and sometimes a 

 similar mark around the right ear." 



In occasional specimens the brownish gray of the flanks extends on to the under surface, 

 giving it a darker cast, instead of the clear white of the normal coloration. Such individuals 

 are supposed by the whalemen to be hybrids between this species and the Blue Whale, and 

 hence are called Bastard Whales. But there is no reason to suppose that the two species 

 hybridize, or that these pecuUar individuals are more than variations from the normal pattern. 



Hair. — The Cetacea have lost all trace of a hairy covering on their bodies, but on certain 

 parts of the head a few hairs still persist, as remnants of what we may suppose was in past 

 ages, a scanty supply, similar perhaps to that of the modern elephants. In the toothed whales, 

 the hairs are no longer found in adults, though young or foetal specimens may show a few in 

 definite spots. Among the whalebone whales, however, a considerable number is retained 

 throughout life. These are restricted to definite parts of the outer surfaces of the jaws, and 

 correspond roughly to the vibrissae or 'feelers' of certain other mammals. They are most 

 numerous in the Right Whales and in the Humpback, but in the Balaenopterae are fewer in 

 number and with a much more definite distribution. The Common Finback possesses two 

 series of these short grayish bristles on each side of the upper jaw. The outer row begins 

 about over the angle of the mouth, and runs to the tip of the snout. It consists of a series of 

 some eight single bristles set at fairly regular intervals parallel with the outer rim of the rostrum 

 and a short distance in from that edge. The second row is nearly parallel to this, of eight or 

 nine bristles, but is closer to the median line. It commences back of the blowholes and passes 

 anteriorly along the median ridge of the snout, to a point some distance behind the tip. On 

 each side of the lower jaws are two other series of short whitish bristles. One consists of some 

 nine in all, set at considerable intervals along the middle of the outer edge of the ramus to a 

 point just in front of the eye. The other is a short vertical row at the tip of the jaw on each 

 side, made up of about fourteen hairs, rather close together (Lillie, 1910). 



A recent investigator (Japha, 1911) has made a microscopic study of these hairs. He 

 finds that their structure is much like that of the ordinary mammalian hair, except that the 

 sebaceous glands are lacking. They have a well developed bulbus, supplied with blood vessels, 

 and, what is of great interest, nerve endings. This latter fact indicates that the hairs are 

 sensory and as had been previously suggested, are probably tactile organs, whose function may 

 be to indicate the presence of the minute crustaceans or small fishes on which these whales 

 feed. 



Baleen. — The baleen or whalebone plates are about 430 in number counting along the 



