259 



ther, re-enters the shell, and the next moment again 

 issues from it, to iix a new cable a little farther off. 



Did you take notice of a mark of skill expressed by 

 our muscle ] She has just now spread the first thread ; 

 to assure herself of the goodness of it, she immediately 

 puts it to tiie proof; drawing it strongly towards her, 

 as though she would break it. It has resisted this 

 effort ; and, satisfied with the experiment, she has pro- 

 ceeded to stretch out the second thread, which she has 

 tried iike the first. 



These cords, which the sea-muscles^ spin with so 

 much art, are, in reality, as serviceable to them as ca- 

 bles are to a ship. You ask me, whether they can 

 weigh anchor! Divers experiments prove they are not 

 endued with that ingenuity. It was not necessary for 

 them. But they sometimes drive with their anchors ; 

 it therefore behoves them to have fresh cables in re- 

 serve. 



Thus the sea has its spinners as well as the earth. 

 Muscles are at sea the same that caterpillars are on 

 land. There is, nevertheless, a remarkable difference 

 between them. The work of caterpillars answers ex- 

 actly to that of gold wire-drawers. The silk thread is 

 moulded by passing through the mouth of the spinner, 

 and the caterpillar gives it what length she pleases; 

 which, in certain cones, consists of several hundred 

 feet. The labour ofr muscles may rather be compared 

 to that of workmen who cast metals. The spinning in- 

 strument of these shell-fish is a real mould, which does 

 not only determine the thickness of the thread, but also 

 its length, which is always equal to that of the spinning 

 instrument, or tongue. 



The pinna? marince, which are species of very large 

 muscles, are more dextrous spinners still. Their 

 threads, which are at least seven or eight inches long, 

 are extremely fine, and curious works are made with 

 them. If muscles are caterpiilers of the sea, pinna? 



