110 NATURAL HISTORY. 
you that the great object of breathing is to change dark 
blood into red blood, and that the blood, as it returns to 
the heart from all parts of the body of a dark color, is 
sent to the lungs to be changed to red blood, before it is 
again distributed over the system. Red blood is neces- 
sary to every organ, to have life go on; and if it could 
be supplied to all the organs without breathing, then the 
breathing could be suspended without destroying life. 
Now the Whale has large reservoirs where the red blood 
accumulates while it is up at the surface of the water 
breathing. When, therefore, it goes down, every part 
of its body is supplied with red blood from these reser- 
voirs. When the supply is gone, the Whale feels un- 
comfortable, and rises to the surface to renew the sup- 
ply. The nostrils are near the highest part of the head, 
so that it can breathe as soon as it reaches the surface. 
These orifices, and also the openings of the ears, have 
valves, which can close so tightly that, even when subject- 
ed to the pressure of a great depth of water, not a drop 
can enter. 
188. The nostrils are the blow-holes. ‘The Whale has 
a curious apparatus for spouting. There are two large 
pouches under the nostrils, which can be filled with wa- 
ter taken in by the mouth. Here it can be retained by 
an arrangement of valves till the Whale wishes to spout ; 
and then, by a forcible compression of the pouches, the 
water is thrown upward through the blow-holes, the 
valves of which are pushed open. 
189. The true Whales are of two kinds or families: 
1. The Spermaceti Whale, which has teeth in the lower 
jaw. 2. The Whalebone Whale, which has no teeth. 
Of the Spermaceti Whales there are two species. the 
most common of which, the Cachelot, or Sperm Whale, 
Fig. 93 (p. 111), I will notice. When full-grown it is 
from seventy to eighty feet long. The capture of this 
animal is attended with even greater danger than that 
of the Greenland Whale, on account of its formidable 
