ANIMAL LIFE IN PONDS & STREAMS 



covered will almost certainly prove to be young 

 mussels. We must examine them under the micro- 

 scope to make sure. Then we shall see, if young 

 mussels they be, very minute and very thin-shelled 

 little creatures; the edges of their shells are armed 

 with teeth and are quite unlike the highly polished 

 and smooth shells of the parent mussel. We shall 

 also see a long thread issuing from the animal 

 within the shell. If we are examining the young 

 mussel in water we shall notice that it is constantly 

 snapping its two shells together. 



Had we left these young mussels undisturbed, 

 a very curious life they would have led. They 

 would have remained attached to their parent for 

 some little time probably, or some of them might 

 have fallen to the muddy bed of the pond. Their 

 behaviour in either case would be the same. The 

 long threads that we have already examined would 

 have floated in the water and, directly they were 

 touched by a passing fish, the little shells would 

 begin to snap violently. The lucky ones would not 

 snap in vain for they would close upon the fin or 

 tail of the fish and then their snapping would cease. 

 Like the bulldog, these little mussels may take a 

 long time in getting hold but when once they have 

 managed to fasten their teeth into anything it is 

 well-nigh impossible to make them let go. Usually 

 they never let go, but are carried away by the fish. 

 In most cases, the irritation they set up in the flesh 

 of their new-found foster parent causes a swelling 

 to occur with the result that the little mussels are 



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