It was Aristotle in his History of Animals (521b) who first 

 classified whales, porpoises, and dolphins as Cetacea, ra ktity] 

 dlov SeXifLs Kal (pcoKaiva Kal (paKaiva. Aristotle's account of the 

 Cetacea was astonishingly accurately written, and quite evi- 

 dently from firsthand knowledge of these animals. 



While most dolphins are inhabitants of the seas, there are 

 some that live in rivers, and quite a few that are denizens of 

 fresh-water rivers removed many miles from the sea. With one 

 exception the diet of dolphins is principally fish. The one excep- 

 tion is Sotalia teuszii, which lives in the Kamerun River, and is 

 believed to feed exclusively on vegetable matter. The Ting Ling 

 dolphin (Lipotes vexillifer) lives in Ting Ling Lake, six hun- 

 dred miles up the Yang-tse-Kiang. Another dolphin, the Susu 

 or Ganges dolphin {Platanista gangetica) of Brahmapootra, the 

 Ganges, and the Indus, has lenseless eyes and is almost blind. 

 The fresh-water dolphins belong in the family Platanistidae. 



It is of interest to note that, in connection with the vegetable 

 feeding habits of the Kamerun dolphin, Lycophron, in his Alex- 

 andra, makes his dolphins feed on trees, and Ovid, in the Meta- 

 morphoses (III, I, 202), describes a flood in which the dolphins 

 take possession of the woods. Nonnus Panopolitanus, in the 

 Dionysiaca (VI, 265-266), also describes dolphins as feeding on 

 trees. 



The normal range of length of dolphins is from 5 to 14 feet; 

 the larger species, the whales, are considerably longer. Brain 

 weight is between 1600 and 1700 grams in the familiar dolphins, 

 and reaches 9200 grams and more in the whales. The large brain 

 is associated with what, all observers familiar with these animals 

 agree, is a quite considerable intelligence. 



Here we must pause to make a plea for the proper usage of 

 common names. The term "porpoise" refers to the small, beak- 

 less Delphinidae, which have a triangular dorsal fin and spade- 

 shaped teeth. The name "dolphin" embraces all other members 

 of the family, except the larger forms, which are called whales. 



