216 NATURAL HISTORY. 



to contain nine million of eggs. Fishes being thus pro- 

 lific, societies of them, or shoals, as they are called, are 

 often immense in multitude. They would be too abund- 

 ant were their number not kept down by various causes. 

 Many of the eggs are destroyed, and then of the young 

 fish so many are eaten by other fish, and are killed in va- 

 rious ways, that few of them comparatively come to ma- 

 turity. 



364. Some fishes present a strong contrast to all this 

 in the number of their young. This is the case with that 

 rapacious fish, the Shark, thus illustrating the Divine wis- 

 dom and benevolence. It produces but two eggs. The 

 eggs of some species of the Sharks are great curiosities. 

 They are of firm texture, and of a purse-like shape, with a 

 long tendril extending from each corner of it, as seen in 

 Fig. 168. These tendrils, coiling around seaweed or any 



Fig. 168. Egg of Shark. 



other substance, serve to anchor the egg securely. The 

 purse is thin at the end where the head of the young fish 

 is, and when it is in a fit state to come out, it breaks its 

 way through this end. Some other fishes lay similar 

 eggs. They are sometimes picked up by the sea-shore, 

 and are called Mermaids' Purses. 



365. Fishes supply quite a large portion of the food of 

 the human family. An immense amount of capital is 

 employed in carrying on the fisheries, and in some quar- 

 ters a large part of the population are engaged in them. 



