112 NATURAL HISTORY. 
enough to take in a body of the size of a man. But one 
young is produced at a time, and this is about fourteen 
feet long. The milk of the mother Whale is very much 
like that of quadrupeds. 
192. Whalebone Whales are as large as the Sperm 
Whales. There are two species, the Greenland Whale, 
and the Rorqual. The former is the best known, and 
is altogether the most valuable, because it furnishes the 
most blubber and the best whalebone. These whales 
have no teeth, but instead have a remarkable apparatus 
for taking their food, which consists of very small sea- 
animals of various kinds. The whalebone is the frame- 
work of the food-catching apparatus; it is in the head, 
in laminee or plates to the number of three or four hund- 
red. All of these are fringed with fibres extending down 
into the mouth. Now, when the Whale feeds, it rushes 
through the water with its huge mouth wide open, throw- 
ing out the water that enters the mouth by spouting 
through the blow-holes. The consequence is, that as the 
water passes through the fringes, the little animals in it 
are caught by them, and then are swallowed. The 
throat, in contrast with that of the Sperm Whale, is so 
narrow, that what an ox could easily swallow would 
choke this immense animal. 
193. The Dolphin family of the Cetacea includes, be- 
sides the Porpoise and the Dolphin, many animals ordi- 
narily called Whales. They all have teeth in greater 
number than any other Mammals, some of them even 
over a hundred in each jaw. The Porpoise occurs in 
large numbers in all the seas of Europe, and on the coasts 
of America. It is abundant in our bays and large rivers. 
Its length is from four to eight feet. It lives on her- 
rings, mackerel, salmon, ete. It is the most common and 
abundant of all the Cetacea. The blubber yields a very 
fine oil. Its skin is tanned, and the leather is used par- 
ticularly for the upper leather of boots and shoes. It is 
amusing to see the Porpoises rise to the surface, and 
