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 Whale 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 pun 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 



