Molluscs 139 



come covered with mother-of-pearl, and 

 so cunningly are they insinuated that 

 shells only four inches long present 

 twenty or more of these, neatly arranged 

 in rows a wonderful example of manual 

 dexterity inspired by an almost fanatical 

 religious faith. 



A vast galaxy of animal life flourishes 

 in any neglected water supply, and in 

 1912 nearly 100 tons of a fresh-water 

 mussel (Dreissenoia) were removed from 

 a water-pipe at Hampton-on-Thames, 

 the shells reducing a 36-inch bore to a 

 mere g-inch. Mussels are not the only 

 animals to inhabit water-pipes. First 

 there may appear microscopic sponge 

 pores and polyzoa, and the branching 

 growths therefrom may soon create a 

 jungle giving sanctuary to worms, crus- 

 taceans and especially molluscs of all 

 kinds. Even eels and flounder may join 

 these strange colonies which, adapting 

 themselves to altered conditions, prosper 



