683 



A HISTORY OF 



tiou ; anJ a single muscle or oyster, if there 

 were no other in the world, would quickly 

 replenish the ocean. As the land-snail, from 

 its being best known, took the lead in the 

 former class, so the fresh-water muscle, for 

 the same reason, may take lead in this. The 

 life and manners of such as belong to the sea 

 will be best displayed in the comparison. 



The muscle, as is well known, whether 

 belonging to fresh or salt-water, consists of 

 two equal shells, joined at the back by a 

 strong, muscular ligament, that answers all 

 the purposes of a hinge. By the elastic con- 

 traction of these the animal can open its shell 

 at pleasure, about a quarter of an inch from 

 each other. The fish is fixed to either shell 

 by four tendons, by means of which it shuts 

 them close, and keeps its body firm from 

 being crushed by any shock against the walls 

 of its own habitation. It is furnished, like all 

 other animals of this kind, with vital organs, 

 though these are situated in a very extraor- 

 dinary manner. It has a mouth furnished 

 with two fleshy lips; its intestine begins at 

 the bottom of the mouth, passes through the 

 brain, and makes a number of circumvolutions 

 through the liver; on leaving this organ, it 

 goes on straight into the heart, which it pe- 

 netrates, and ends in the anus ; near which 

 the lungs are placed, and through which it 

 breaths, like those of the snail kind; and in 

 this manner its languid circulation is carried 

 on. 



But the organs of generation are what most 

 deserve to excite our curiosity. These con- 

 sist in each muscle of two ovaries, which are 

 the female part of its furniture, and of two se- 

 minal vessels, resembling what are found in 

 the male. Each ovary and each seminal ves- 

 sel, has its own proper canal ; by the ovary- 

 canal the eggs descend to the anus ; and there, 

 also, the seminal canals send their fluids to 

 impregnate them. By this contrivance, one 

 single animal suffices for the double purposes 

 of generation ; and the eggs are excluded and 

 impregnated by itself alone. 



As the muscle is thus furnished with a kind 

 of self-creating power, there are few places 

 where it breeds, that it is not found in great 

 abundance. The ovaries usually empty them- 



M. Mery. Anat, de Moules d'Etang. 



selves of their eggs in spring, and they are 

 replenished in autumn^ For this reason they 

 are found empty in summer and full in winter. 

 They produce in great numbers, as all bival- 

 ved shell-fish are found to do. The fecun- 

 dity of the snail kind is trifling in comparison 

 to the fertility of these. Indeed it may be as- 

 serted as a general rale in nature, that the 

 more helpless and contemptible tlie animal, 

 the more prolific it is always found. Thus 

 all creatures that are incapable of resisting 

 their destroyers, have nothing but their quick 

 multiplication, for the continuation of their 

 existence. 



The multitude of these animals in some 

 places is very great; but, from their defence- 

 less state, the number of their destroyers are 

 in equal proportion. The crab, the cray-fish, 

 and many other animals, are seen to devour 

 them ; but the trochus is their most formidable 

 enemy. When their shells are found deserted, 

 if we then obserre closely, it is most proba- 

 ble we shall find that the trochus has been 

 at work in piercing them. There is scarce 

 one of them without a hole in it; and this 

 probably was the avenue by which the ene- 

 my entered to destroy the inhabitant. 



But notwithstanding the number of this 

 creature's animated enemies, it seems still 

 more fearful of the agitations of the element 

 in which it resides; for if dashed against rocks, 

 or thrown far on the beach, it is destroyed 

 without a power of redress. In order to guard 

 against these, which are to this animal the 

 commonest and the most fatal accidents, al- 

 though it has a power of slow motion, which 

 I shall presently describe, yet it endeavours 

 to become stationary, and to attach itself to 

 any fixed object it happens to be near. For 

 this purpose, it is furnished with a very sin- 

 gular capacity of binding itself by a number 

 of threads to whatever object it approaches ; 

 and these Reaumur supposed it spun artifi- 

 cially, as spiders their webs which they 

 fasten against a wall. Of this, however, later 

 philosophers have found very great reason 

 to doubt. It is therefore supposed that these 

 threads, which are usually called the beard 

 of the muscle, are the natural growth of the 

 animal's body, and by no means produced at 

 pleasure. Indeed, the extreme length of this 

 beard in some, which far exceeds the length 



