No. IX. THE CETACEA, OR WHALES. 



THE mere fact that the Whales are exclusively 

 inhabitants of the water, is usually held to be a 

 sufficient proof that they should be included among 

 the fishes. In fact, it is generally considered that all 

 sub-aquatic creatures, be they mammals, fish, Crustacea, 

 or radiates, may be included under the one compre- 

 hensive title. 



As far as the whales are concerned, there is certainly 

 some ground for the idea. Their habits and mode of 

 life, their food, and their very form, so closely resemble 

 those of the fishes that we can scarcely wonder if these 

 animals are popularly supposed to form part of that 

 group. We have only to look a little more closely into 

 their structure, however, to find that they have nothing 

 in common with fishes. 



An examination of their mode of breathing is alone 

 sufficient to point out the true position of the whales 

 in the animal kingdom. 



It is well known that all the fishes respire by means 

 of gills, by the agency of which the necessary oxygen 

 is extracted from the water which they inhabit. But the 

 whales, like all other mammals, are obliged to breathe 

 atmospheric air by means of lungs, for which purpose 

 they are compelled to rise to the surface of the water. 

 Were they prevented from doing so, they would be 

 drowned just as would any other mammal under 



