CETACEANS 
WHALES, DOLPHINS AND PORPOISES 
(Cetacea) 
Few persons associate whales with the four-footed beasts of 
the land. So modified are they for the peculiar life that they 
lead that practically no external resemblance to their true kindred 
remains, and it is not surprising that the popular mind classes 
them as fish, to which, however, they bear no relationship. 
Whales are practically devoid of hair, which is characteristic 
of most mammals, its place in retaining the heat of the body 
being taken by the thick coating of fat or ‘‘blubber” lying just 
beneath the skin. There is no external trace of hind limbs and 
the fore-limbs are modified into flat flippers for swimming, while 
the tail is flat and forked like that of a fish, but it is flattened 
horizontally instead of vertically. There is practically no neck 
and the head, which is often very large, joins directly with the 
body. It is but natural, therefore, that the bones of the neck are 
very short and often joined solidly together. Whales have no 
close relationship with any other group of mammals and even 
the oldest fossil whales that have been discovered present much 
the same structure as the living species. Though they were 
undoubtedly descended from some form of land mammal, the 
change to an aquatic life must have taken place at a very remote 
period. As has been suggested, the immediate ancestors of the 
whales probably became adapted to a life on the shores of rivers 
and acquiring the habit of swimming were eventually carried out 
to sea, where peculiar environment has brought about their pre- 
sent structure. 
The cetaceans are entirely carnivorous, and their food 
generally consists of small mollusks, shrimps and fishes. They 
frequently associate in companies or ‘‘schools” and are for the 
most part inoffensive and rather timid. In size they vary from 
the smallest porpoises, somewhat less than ten feet long, to the 
largest whales which reach a length of sixty to eighty-five feet 
