72 



CETACEA. 



baleen can live on large fishes ; but the extreme narrowness of the 

 gullet (that of B. maxtmus barely allowed the passage of the closed 

 human hand, and that of B. minimus was certainlj' narrower than 

 that of an ordinary-sized cow), added to the want of teeth, and the 

 Avant of proper authenticated information on the subject, are strong 

 arguments in favour of the hypothesis that they do not. — Knox, Cat. 

 Prep. Whale, 16. 



Professor Eschricht proposes to divide the \\Tiales into gi'oups 

 according to their food, as given at p. 65. I suspect that they vaiy 

 their food to a considerable extent at different periods of the year 

 and under different circumstances. 



Professor Eschricht (in Fordhandl. Skand. Naturf. Kiobenh. 1847, 

 8vo, 18-19, p. 103) has published a paper on the geographical distri- 

 bution of some of the Northern Whales, with a map, by which it 

 appears that Balcena Ili/sticetus in Baffin's Bay lives in from latitude 

 65° to 69° in December to June, and in July and August ascends 

 to 77°. The FinnoUc lives in lat. 76° in the summer, on the coast of 

 North Greenland, and in lat. 69° in South Greenland. The Keporhak 

 in lat. 76° in North Greenland, and in lat. 62° in South Greenland. 



Tlie rarity of theii- occurrence, the difficulty of naturalists ex- 

 amining them when they do occur, and es2)ecially of comparing them 

 with other specimens, explain why the Whalebone \\Tiales have 

 been so imperfectly known ; and, when observed, the sjiecimens are 

 so large that it is almost impossible for the eye of the natiiraUst to 

 take them in as a whole, and to compare the parts in detail. 



The allied species are so aHko externally, that naturalists and 

 others who have had the opportunity of examining them have been 

 inclined to regard the different specimens observed as only states of 

 growth of the same species ; and, for the same reason, the specimens 

 which have been observed in different parts of the world have been 

 regarded as alike ; and thus the belief has become generfil that the 

 species of Whalebone Whales have a very extended geographical 

 distribution. 



The examination and comparison of the few skeletons that have 

 been collected have shown that there are many more species than 

 has been generally supposed, and seem to lead to the conclusion 

 that each species of Whalebone Whale has only a comparatively 

 limited geographical range ; and the observation of whales seems to 

 make it probable that some of them make jieriodical migrations 

 within these limits. 



The study of the subject, and especially of the bones that have 

 been collected, has led me to the following conclusions : — 



1. That, though the adult Whalebone Whales have a large head 

 compared with the size of the body, the head of the foetal specimen 

 is short, and that it increases in size, and especially in length, much 

 more rapidly than the rest of the body. This is veiy a])parent in 

 the llight or Gi'ccnland Whale, where the head of the adult is two- 

 fifths, while that of the new-born is only two-sevenths of the entire 

 length of the animal. These differences are shown by Eschricht in 

 his figures. The head of the new-born and of the adult Cape Whale- 



