162 FISH AS FA THERS. 



eggs ; but anybody who has ever eaten fried cod's-roe 

 must needs have noticed that each individual ovum was 

 so very small as to be almost indistinguishable to the 

 naked eye. Thousands of these infinitesimal specks are 

 devoured before they hatch out by predaceous fish ; 

 thousands more of the young fry are swallowed alive 

 during their helpless infancy by the enemies of their 

 species. Imagine the very fractional amount of parental 

 affection which each of the nine million must needs put 

 up with ! On the other hand, there is a paternally- 

 minded group of cat-fish known as the genus Arius, of 

 Ceylon, Australia, and other tropical parts, the males of 

 which carry about the ova loose in their mouths, or 

 rather in an enlargement of the pharynx, somewhat 

 resembling the pelican's pouch ; and the spouses of these 

 very devoted sires lay accordingly only very few ova, all 

 told, but each almost as big as a hedge-sparrow's egg a 

 wonderful contrast to the tiny mites of the cod-fish. To 

 put it briefly, the greater the amount of protection 

 afforded the eggs, the smaller the number and the larger 

 the size. And conversely, the larger the size of the egg 

 to start with, the better fitted to begin the battle of life 

 is the young fish when first turned out on a cold world 

 upon his own resources. 



This is a general law, indeed, that runs through all 

 nature, from London slums to the deep sea. Wasteful 

 species produce many young, and take but little care of 

 them when once produced. Economical species produce 

 very few young, but start each individual well-equipped 

 for its place in life and look after them closely till they 

 can take care of themselves in the struggle for existence. 



