196 THE HISTORY OF ANIMALS. [ B. Till. 



neither breathe air or water; and there are other animals 

 which procure their food and make their abode in either of 

 these elements. For many that breathe air, and produce 

 their young upon the land, procure their food from the water, 

 where they generally make their abode ; and these are the 

 only animals which appear to be doubtful, for they may be 

 arranged either as terrestrial or aquatic animals. 



2. Of those that breathe water, none have feet or wings, 

 nor seek their food on land ; but many of those that are ter- 

 restrial, and breathe air, do so ; some of them so much so, that 

 they cannot live when separated from the water, as those 

 which are called marine turtles, and crocodiles, and hippo- 

 potami, and seals, and some of the smaller creatures, as the 

 water tortoise and the frog tribe; for all these are suffocated 

 if their respiration is suspended for any length of time. They 

 produce their young and rear them on dry land ; others do 

 so near the dry land, while they reside in the water. 



3. Of all animals the most remarkable in this particular 

 is the dolphin, and some other aquatic animals and cetacea 

 which are of this habit, as the whale and others which have 

 a blowhole ; for it is not easy to arrange them either with 

 aquatic or terrestrial animals, if we consider animals that 

 breathe air as terrestrial, and those that breathe water as 

 aquatics, for they partake of the characters of both classes ; 

 for they receive the sea and eject it through their blowhole, 

 and air through their lungs, for they have this part, and 

 breathe through it. And the dolphin, when captured in nets, 

 is often suffocated, from the impossibility of breathing. It 

 will live for a long while out of water, snoring and groaning 

 like other breathing animals. It sleeps with its snout above 

 the water, in order that it may breathe through it. 



4. It is thus impossible to arrange it under both of these 

 contrary divisions, but it would appear that the aquatic ani- 

 mals must be further subdivided; for they breathe and 

 eject water for the same reason as others breathe air, for 

 the sake of coolness. Other animals do this for the sake 

 of food ; for those animals which obtain their food in the 

 water, must also, at the same time, swallow some of the 

 fluid, and have an organ by which they can eject it. Those 

 creatures which use water instead of air for breathing have 

 gills; those that use it for food have a blowhole. These 



