402 Fishes. 
in the sea, and has fins and a tail instead of legs and feet, 
it resembles in most other respects a seal, and differs from 
fishes, properly so called, in many important points. In- 
deed, it is always included in the class Mammalia, by 
zoologists, as it brings forth its young alive, and nourishes 
them with its milk ; and hence a conceited person, who 
said he knew every fish from the shrimp to the Whale, 
was justly laughed at, as neither the Whale nor the 
shrimp are included in the fishes by zoologists. 
The general form of the Whale's body is that of a fish ; 
but the tail is placed horizontally instead of vertically, 
and the skeleton of the fins exactly resembles that of a 
hand affixed to a contracted arm, though it is covered 
with so thick a skin that no trace of the formation of the 
bones can be discovered externally. There are only two 
fins, which are very small, and close to the head. The 
Whale, however, differs from fishes most materially in its 
having warm blood ; and in its lungs, which are exactly 
the same as those of quadrupeds. Hence, though the 
Whale can remain a long time under water without 
breathing, it is compelled to come to the surface when- 
ever it does breathe, and for this purpose it is furnished 
with two large nostrils, or blow-holes as they are called. 
The blow-holes are most beautifully and curiously con- 
trived to close when the animal sinks under water ; so 
that not a drop of water can enter the lungs, however 
great the pressure may be. The Whale is also provided 
with a very thick skin, containing an immense quantity 
of liquid oil, called the blubber, which is so easily de- 
tached from the flesh, that when a Whale is killed, the 
blubber, which is sometimes two feet thick, is taken off 
by passing a common spade between it and the body. 
This thick oily skin is a non-conductor of heat, and is 
thus admirably adapted for preventing ihe warm blood 
of the Whale from being chilled by the cold of the water. 
The true fishes, which are unprovided with such a cover- 
ing, have cold blood, and are therefore not susceptible of 
chills. 
The common AJhale has no teeth in either jaw, but its 
mouth is furnished with a kind of fringe of numerous 
long horny lamina^ which are what we call whalebone, 
