MAMMALIA 



277 



being provided with numerous frayed-out plates of baleen or whalebone, 

 suspended from the upper jaw, Fig. 179 and serving to strain out small 

 organisms from the water that the whale gulps into its enormous mouth 

 and then forces out through this whalebone strainer. 



Among the smaller members of the toothed forms are the dolphins 

 Fig. 1 80, and porpoises, of which there are several species, extending 



PIG. 181. Sperm whale, Physeter macrocephalus. (From Hegner, College Zoology.) 



from 5 to 15 feet in length. They are familiar to most people who have 

 taken ocean trips, from their habit of "playing" about the bows of 

 a vessel. 



The sperm whale, Physeter macrocephalus, Fig. 181, is the largest 

 of the toothed whales, reaching a length of 75 feet. 



>-.. 



(After Rabot, Whale 



PIG. 182. Sulphur-bottom whale, Balaenoptera musculus. 

 Fisheries of the World.) 



The largest of the whales is the sulphur-bottom, Balaeoptera 

 culus, Fig. 182, which, according to Hegner, reaches a length of 95 

 feet and weight of about 294,000 pounds; the late F. W. True, an au- 

 thority on the Cetacea, gave the maximum length as somewhat less 

 than this. At any rate this is the largest living animal, and perhaps 

 the largest that has ever lived, for while some of the extinct reptiles were 

 longer, they were probably not so bulky as this whale. Another large 



