FISHES. 849 
young. It has no lungs, and its mode of breathing is like 
that of other fishes, except that its gills are fixed, and the 
water escapes by five elongated apertures on each side. 
Some of the Sharks produce their young alive, and others 
lay eggs or, rather, horny cases of an oblong shape, with 
long tendrils, at each of the four corners. After the young 
Sharks are hatched, these curious cases are often washed 
on shore, and are called mermaids' purses. 
The bones of the Shark are like gristle, and very differ- 
ent from those of most other fishes. Hence all the fishes 
with bones similar to those of the Shark are placed in a 
separate order and called cartilaginous fishes. 
The White Shark is sometimes found weighing nearly 
two thousand pound*. The throat is often large enough 
to swallow a man ; and a human body has sometimes been 
found entire in the stomach of this tremendous animal. 
He is furnished with six rows of sharp triangular teeth, 
amounting in the whole to one hundred and forty-four, 
serrated on their edges, and capable of being erected or 
depressed at pleasure, owing to a curious muscular me- 
chanism in the palate and jaws of the Shark. The whole 
body and fins are of a light ash-colour ; the skin rough, 
and employed to smooth cabinet work, or to cover small 
boxes or cases. His eyes are large and staring, and he 
possesses great muscular strength in his tail and fins. 
Whenever he spies, from the deepest recesses of the sea, a 
man swimming or diving, he bolts from the place, darts 
up to his prey, and if unable to take in the whole, or 
snatch away a limb, he follows for a long time the boat or 
vessel in which the more nimble swimmer has found a safe 
and opportune retreat : but seldom does he let any one 
escape his jaws, and get off entire. Sir Brook Watson 
was swimming at a little distance from a ship, when he 
saw a Shark making towards him. Struck with terror at 
its approach, he cried out for assistance. A rope was in- 
stantly thrown ; but even while the men were in the act 
