690 



A HISTORY OF 



from never seeing oysters copulate, erroneous- 

 ly supposed to be the male by which their 

 spawn was impregnated. 



The oyster differs also from the muscle in 

 being utterly unable to change its situation. 

 The muscle, as we have observed, is capa- 

 ble of erecting itself on an edge, and going 

 forward with a slow laborious motion. The 

 oyster is wholly passive, and endeavours by 

 all its powers to rest fixed to one spot at the 

 bottom. It is entirely without that tongue 

 which we saw answering the purposes of an 

 arm in the other animal ; but nevertheless 

 is often attached very firmly to any object it 

 happens to approach. Rocks, stones, pieces 

 of timber, or sea-weeds, all seem proper to 

 give it a fixture, and to secure it against the 

 agitation of the waves. Nothing so common 

 in the rivers of the tropical climates as to see 

 oysters growing even amidst the branches of 

 the forest.. Many trees which grow along the 

 banks of the stream often bend their branches 

 into the water, and particularly the mangrove, 

 which chielly delights in a moist situation. 

 To these the oysters hang in clusters, like 

 apples upon the most fertile tree ; and in pro- 

 portion as the weight of the fish sinks the 

 plant into the water, where it still continues 

 growing, the number of oysters increase, and 

 hang upon the branches. Thus there is no- 

 thing that these shell-fish will not stick to; 

 they are often even found to stick to each 

 other. This is effected by means of a glue 

 proper to themselves, which, when it cements, 

 the joining is as hard as the shell, and is as 

 difficultly broken. The joining substance, 

 however, is not always of glue ; but the ani- 

 mal grows to the rocks, somewhat like the 

 muscle, by threads ; although these are only 

 seen to take root in the shell, and not, as in 

 the muscle, to spring from the body of the fish 

 itself. 



Oysters usually cast their spawn in May, 

 which at first appear like drops of candle- 

 grease, and stick to any hard substance they 

 fall upon. These are covered with a shell in 

 two or three days ; and in three years the ani- 

 mal is large enough to be brought to market. 

 As they invariably remain in the places where 

 they are laid, and as they grow without any 

 other seeming food than the afflux of sea- 

 water, it is the custom at Colchester, and 

 other parts of the kingdom, where the tide 



! settles in marshes on land, to pick up great 

 quantities of small oysters along the shore, 

 which, when first gathered, seldom exceed the 

 size of a sixpence. These are deposited in 

 beds where the tide comes in, and in two or 

 three years grow to a tolerable size. They 

 are said to be better tasted for being thus 

 sheltered from the agitations of the deep : and 

 a mixture of fresh water entering into these 

 repositories, is said to improve their flavour, 

 and to increase their growth and fatness. 



The oysters, however, which are prepared 

 in this manner, are by no means so large as 

 those found sticking to rocks at the bottom of 

 the sea, usually called rock-oysters. These are 

 sometimes found as broad as a plate, and are 

 admired by some as excellent food. But 

 what is the size of these compared to the oys- 

 ters of the East Indies, some of whose shells I 

 have seen two feet over ! The oysters found 

 along the coast of Coromandel are capable of 

 furnishing a plentiful meal to eight or ten men; 

 but it seems universally agreed that they are 

 no way comparable to ours for delicacy or 

 flavour. 



Thus the muscle and the oyster appear to 

 have but few distinctions, except in their shape, 

 and the power of motion in the former. 

 Other bivalved shell-fish, such as the cockle, 

 the scallop, and the razor-shell, have differ- 

 ences equally minute. The power of chang- 

 ing place, which some of them effect in a 

 manner quite peculiar to themselves, makes 

 their greatest difference. The scallop is par- 

 ticularly remarkable for its method of moving 

 forward upon land, or swimming upon the 

 surface of the water. When this animal finds 

 itself deserted by the tide, it makes very re- 

 markable efforts to regain the water, moving 

 towards the sea in a most singular manner. 

 It first gapes with its shell as widely as it can, 

 the edges being often an inch asunder ; then 

 it shuts them with a jerk, and by this the 

 whole animal rises five or six inches from the 

 ground. It thus tumbles any how forward, 

 and then renews the operation until it has at- 

 tained its journey's end. When in the water 

 it is capable of supporting itself upon the sur- 

 face ; and there opening and shutting its shells, 

 it tumbles over and over, and makes its way 

 with some celerity. 



The Pivot, or Razor-shell, has a very dif- 

 ferent kind of motion. As the former moves 



