228 . CETACEA 



brain is large relatively to the size of the animal, very round in 

 form, and with its surface divided by sulci into very numerous and 

 complex convolutions. The kidneys are deeply lobulated. The 

 testes are abdominal. There are no vesiculae seminales, nor os 

 penis. The uterus is bicornuate, and the placenta nondeciduate 

 and diffuse. The mammse are two in number, and the nipples 

 placed in depressions on each side of the vulva. The principal 

 ducts of the gland are dilated during lactation into large reservoirs, 

 into which the milk collects, and from which it is injected by the 

 action of a compressor muscle into the mouth of the young animal, 

 by which means the process of sucking under water is greatly 

 facilitated and expedited. 



The animals of the order Cetacea abound in all known seas, 

 and some species are inhabitants of the larger rivers of South 

 America and Asia. Their organisation necessitates passing their life 

 entirely in the water, as on land they are absolutely helpless. 

 They have, however, to rise very frequently to the surface for the 

 purpose of respiration ; and, in relation to the constant upward and 

 downward movement in the water thus necessitated, their principal 

 instrument of motion, the tail, is expanded horizontally, quite 

 unlike that of a fish, whose movements are mainly in straight- 

 forward or lateral directions. The position of the respiratory orifice 

 or nostril on the highest part of the head is very important for 

 this mode of life, since it is the only part of the body of which 

 the exposure above the surface is absolutely necessary. Of the 

 numerous erroneous ideas connected with natural history, few are 

 so wide spread and still so firmly believed, notwithstanding repeated 

 expositions of its falsity, as that the Cetacea spout out through 

 their blowholes water taken in at the mouth. The fact is, the 

 " spouting," or more properly " blowing," of the Whale is nothing 

 more than the ordinary act of expiration, which, taking place at 

 longer intervals than in land animals, is performed with a greater 

 amount of emphasis. The moment the animal rises to the surface 

 it forcibly expels from its lungs the air taken in at the last inspira- 

 tion, which of course is highly charged with watery vapour in 

 consequence of the natural respiratory changes. This, rapidly 

 condensing in the cold atmosphere in which the phenomenon is 

 generally observed, forms a column of steam or spray, which has 

 been erroneously taken for water. It also often happens, especially 

 when the surface of the ocean is agitated into waves, that the 

 animal commences its expiratory puff before the orifice has quite 

 cleared the top of the water, some of which may thus be driven 

 upwards with the blast, tending to complete the illusion. In 

 hunting Whales the harpoon often pierces the lungs or air passages 

 of the unfortunate victim, and then fountains of blood may be 

 forced high in the air through the blowholes, as commonly depicted 



