310 ANIMAL SKETCHES. CHAP. 



the gill of the parent, the neighbourhood of fish such as 

 perch or sticklebacks seeming to have some influence in 

 determing their ejection. They then swim by flapping 

 their valves, and ere long attach themselves, by fine 

 threads with which they are provided, to one of the fish, 

 and hang there, snapping their valves until they bury 

 them in the skin of the fish. Becoming thus enveloped 

 in the skin they there undergo a complete metamorphosis, 

 by which they are converted into tiny mussels which are 

 set free and drop to the bottom. This, in the case of the 

 mussel, is Nature's provision for the preservation of the 

 race. Were the fry hatched as free-swimming embryos, 

 they would inevitably be swept away by the seaward cur- 

 rent of the river, and the mussel, as a freshwater race 

 would be unable to maintain its existence. 



The existence of the adult oyster, to whom we must 

 now return after this digression, is not altogether free 

 from danger. What with sponges tunnelling in their 

 shells, dog-whelks boring neat holes and sucking their 

 sapid juices, and artful starfishes waiting for them to gape, 

 and then inserting insidious fingers, they have a rather a 

 lively time of it. But the short, active life of the oyster- 

 fry is beset with yet greater dangers. It is a sensitive 

 little thing, and succumbs to the cold of inclement seasons. 

 It is also a tasty little morsel, and is greedily swallowed by 

 any marine monster that has a big enough mouth for 

 there are epicures in plenty among the marines. And 

 when, tired of the giddy dance of youth, he would fain settle 

 down into sedate and sedentary bearded oysterhood, it is 

 but too probable that the inexorable tides and currents, of 

 the very existence of which he, like many another gay 

 youngster, was doubtless ignorant, have swept him out 

 into the deep sea, or to some uncongenial spot, where he 

 is choked so soon as he endeavours to settle. 



