The Rising Generation 29 



with the result that on the completion of 

 his nursing duties he is much emaciated 

 and probably frequently dies of starvation. 



In the little bitterling carp of Central 

 Europe we have an example of a fish 

 that foists its eggs upon a foster parent 

 any fresh-water mussel of large size. 

 Spawning continues intermittently for 

 about two days, the male enticing the 

 lady of his choice towards a mussel. 

 Eventually the bride protrudes a long 

 ovipositor and inserts it in the inhalent 

 siphon tube of the mollusc. If all goes 

 well the baby fish grow fast and leave 

 their strange nursery about a month 

 after spawning when about half an inch 

 in length. The mussel is none the worse 

 for its experience, and in its turn spends 

 an early stage of its life encysted on the 

 sides of the fish. 



Parental parasitism of this kind is to 

 be met with in many different types of 

 animals, the parasite merely making use 



