BIVALVE!) SHELL-FISH. 



like those of the snail kind; and in this man- 

 ner its languid circulation is carried on. 1 



But the organs of generation are what most 

 deserve to excite our curiosity. These consist 

 in each mussel of two ovaries, which are the 

 female part of its furniture, and of two seminal 

 vessels, resembling what are found in the 

 male. Each ovary and each seminal vessel, 

 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 impreg- 

 nate 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 mussel 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- 

 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 bivalved 

 shell-fish are found to do, The fecundity 

 of the snail kind is trifling in comparison to 

 the fertility of these. Indeed it may be as- 

 serted as a general rule in nature, that the 

 more helpless and contemptible the 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 ex- 

 istence. 



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 observe closely, it is most probable 

 we shall find that the trochus has been at work 

 in piercing them. There is scarcely one of 

 them without a hole in it ; and this probably 

 was the avenue by which the enemy entered 

 to destroy the inhabitant. 



But notwithstanding the numbers 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 singular 

 capacity of binding itself by a number of 



1 M. Meiy. Anat. des Monies d'Etang. 



threads to whatever object it approaches ; and 

 these Reaumur supposed are spun artificially, 

 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 mussel, 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 of the body, 

 seems impossible to be manufactured by the 

 thrusting out and drawing in of the tongue, 

 with the glutinous matter of which the French 

 philosopher supposed those threads were formed. 

 It is even found to increase with the growth 

 of the animal ; and as the mussel becomes lar- 

 ger and older, the beard becomes longer, and 

 its filaments more strong. 2 Be this as it will, 

 nothing is more certain than that the mussel 

 is found attached by these threads to every 

 fixed object ; sometimes, indeed, for want of 

 such an object, these animals are found united 

 to each other ; and though thrown into a lake 

 separately, they are taken out in bunches of 

 many together. 



To have some fixed resting place where the 

 mussel can continue, and take its accidental 

 food, seems the state that this animal chiefly 

 desires. Its instruments of motion, by which 

 it contrives to reach the object it wants to 

 bind itself to, is that muscular substance re- 

 sembling a tongue, which is found long in 

 proportion to the size of the mussel. In some 

 it is two inches long, in others not a third part 

 of these dimensions. This the animal has a 

 power of thrusting out of its shell ; and with 

 this it is capable of making a slight furrow in 

 the sand at the bottom. By means of this 

 furrow it can erect itself upon the edge of its 

 shell ; and thus continuing to make the furrow 

 in proportion as it goes forward, it reaches out 

 its tongue, that answers the purpose of an arm, 

 and thus carries its shell edge-ways, as in a 

 groove, until it reaches the point intended. 

 There, where it determines to take up its re- 

 sidence, it fixes the ends of its beard, which 

 are glutinous, to the rock or the object, what- 

 ever it be ; and thus, like a ship at anchor, 

 braves all the agitations of the water. Some- 

 times the animal is attached by a large num 

 her of threads ; sometimes but by three or four, 

 that seem scarce able to retain it. When the 

 mussel is fixed in this manner, it lives upon 

 the little earthy particles that the water tran- 

 sports to its shells, and perhaps the flesh of the 

 most diminutive animals. However, it does 

 not fail to grow considerably ; and some of 

 this kind have been found a foot long. I 

 have seen the beards a foot and a half; and of 



* Mercier du Paty, stir le Bouchots a Moules. Tom. 

 ii. de 1'Academie de la Rochelle. 



