214 THE INFANCY OF ANIMALS 



yielded 639,000, the heavier 689,000 ; and again, of two 

 grey gurnards, one weighed izf oz., and yielded 244,000, 

 the other weighed 14 oz. and yielded 269,000 eggs. Again, 

 take the case of two herrings. One measured ii| in. 

 and yielded 47,000, the other 11 in. and gave only 

 21,000. 



From this list, as Mr. J. T. Cunningham has pointed 

 out, it is clear that the ling is the most prolific and the 

 herring the least, though the herring is a more abundant 

 fish than the ling. This is not so contradictory as at 

 first appears, for the ling is a predaceous fish, and much 

 larger than the herring, and a predaceous fish must 

 necessarily be much larger than the fish on which it preys. 

 Since, then, it is quite clear that fishes producing but a 

 few thousand eggs are often more abundant, in spite of 

 hosts of eneinies, than those which produce millions, we 

 learn that the production of a very large number of eggs 

 usually implies an enormous destruction of eggs and 

 young, either by the action of enemies or by surrounding 

 conditions, or from scarcity of food.- Thus in the case 

 of the herring, which feeds, both during the young and 

 adult stages, on the swarms of minute Crustacea, and 

 other equally small animals, an abundance of food is 

 usually everywhere obtainable ; while only such young 

 ling can survive as succeed in finding smaller fishes than 

 themselves to prey upon, and these are not found every- 

 where, hence hosts must starve to death. A careful 

 survey of the facts shows us that the production of large 

 numbers of eggs and young attains the same result as 

 obtains where but few eggs are laid, and are either care- 

 fully guarded by the parents or are specially protected 

 by some other means. The spiny dog-fish, for example, 

 is ovo-viviparous, producing but six or seven young at 



