16 MARINE AND AQUATIC TEESPASSERS. 



the animals when compared with their measurement in 

 feet and inches. A foot more or less, either in length 

 or thickness, does not seem very much on paper, but 

 in actual bulk a foot short makes the difference be- 

 tween a giant and a dwarf. 



Take ourselves for example. A man of five feet six 

 inches high is looked upon not to say down upon 

 almost as a dwarf, while a man of six feet six inches 

 is nearly a giant. Indeed, a man who measures six 

 feet in height looks like a little boy when standing by 

 the side of a man who is only three inches taller, and 

 it may easily be seen that when bulk as well as height 

 have to be taken into consideration, the difference in 

 size is really astounding. 



As a general rule, all the gigantic mammalia of the 

 present day are exclusively vegetarian, such as the 

 elephant, the hippopotamus, the rhinoceros, and the 

 giraffe ; not to mention the various species of buffalo, 

 some of which are but little inferior in bulk to an 

 ordinary elephant. 



Here, however, we have the curious fact that the 

 largest of living mammals are predacious, and that in 

 order to supply their enormous bodies with sufficient 

 food, they must either prey upon a few animals nearly 

 as large as themselves, or upon vast numbers of 

 smaller animals. The former alternative is clearly 

 out of the question, and so they have to fall back upon 

 the latter. 



Some, such as the Greenland Whale, feed upon 

 small molluscs, which they catch in the natural 

 net which fringes their vast mouths. Some, such 

 as the Spermaceti Whale, live mostly on the 



