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 vesicule seminales, nor os 
penis. The uterus is bicornuate, and the placenta nondeciduate 
and diffuse. The mammz 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 passage’s 
of the unfortunate victim, and then fountains of blood may be 
forced high in the air through the blowholes, as commonly depicted 
