336 A DESCRIPTION OF 
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 
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 whenever it does breathe, 
and for this purpose it is furnished with two large nostrils, 
or blow-holes as they are called, through which it breathes. 
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 ; and this curious skin is so easily de- 
tached from the flesh, that when a Whale is killed, the blub- 
ber, which is sometimes two feet thick, is taken off by pass- 
ing 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 the warm blood of the Whale 
from being chilled by the cold of the water. The true 
fishes, which are unprovided with such a covering, have 
cold blood, and are therefore not susceptible of chills. 
