CETACEANS. 
107 
or femur, and the only trace of a hind limb which this gigantic 
animal possesses. The existence of these apparently useless rudi- 
mentary structures has a deep bearing upon the origin and past 
history of Whales, and their relationship to the other Mammalia. 
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 organization necessitates their passing 
their life entirely in the water, as on land they are absolutely help- 
less. 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 horizon- 
tally, quite unlike that of a Fish, whose movements are mainly in 
straightforward or lateral directions. The position of the respi- 
ratory orifice or nostril on the highest part of the head is very 
important for this mode of life, as it is the only part of the body 
the exposure of which above the surface is absolutely necessary. 
Of the numerous erroneous ideas connected with natural history, 
few are so widespread and still so firmly believed 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 M^hale is nothing more than the ordinary act of breathing, 
performed at longer intervals than is the case with land animals. 
The moment the Whale rises to the surface it forcibly expels from 
its lungs the air taken in at the last inspiration, which of course 
is heated and 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 ob- 
served, forms a column of steam or spray, which has been erro- 
neously 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 in 
scenes of Arctic adventure ; but this is nothing more (allowance 
