754 NATURAL HISTORY OF AQUATIC ANIMALS. 



Various ways of supporting the tiles and slates have been devised, cheap forms of which are 

 described in the treatises of Coste and Fraiche. The primary requisite in putting down collectors 

 is that they shall be so placed as not to be covered by mud, especially where the bottom is overlaid 

 with ooze. In such cases they must be supported so as to prevent their falling into the mud, the 

 effect of which would be to make them useless. In practice, I suspect, that it would be well to 

 look after the collectors occasionally and to brush off the mud, because in some places I have 

 noticed that thick deposits of sediment soon collect upon the upper surfaces. This accounts for 

 the fact that several observers have noticed that the spat is disposed to attach itself and survive 

 on the lower surface of the collectors. 



I am informed by Mr. C. P. Hull that the practice of strewing oyster-shells as spat-collectors 

 on hard sea-bottom two or three fathoms deep is becoming quite common on the Connecticut 

 shores of Long Island Sound. Here, the practice is to scatter two hundred and fifty to three 

 hundred bushels of shells over an acre of bottom. The method there has also been so successful 

 and profitable as a means of increasing the area of the oyster fishery that the price of the dead 

 shells has increased and is likely to continue to do so, since the demand is greater than the supply. 

 Mr. Hull, himself a practical oyster-culturist, proposes to introduce this system into practice on 

 his projected plantations on the Chesapeake, where a beginning has already been made by this 

 method under the direction of Captain Hine, at Cherrystone, the superintendent of the firm of 

 Maltby & Co., of Norfolk, now largely interested as planters in the Cherrystone River. This 

 method is the same as that extensively practiced in Europe. 



How AN OYSTER TAKES ON FLESH. Among oystermen the business of fattening or feeding 

 the Oyster is one of the most important, from the fact that upon the condition of the market, 

 able product largely depends its value. Fatness, so called, in the Oyster is a condition wholly 

 different in nature from the state known under that name in stall-fed domestic animals. The 

 turgidity.of the reproductive organs is not usually indicative of fatness, as it appears some authors 

 have supposed, Mobius being the only one who has apprehended its true nature. The word " fat," 

 as applied to indicate the condition of the Oyster when in flesh, is a misnomer, since it is not fat 

 at all which is the immediate cause of the condition of plumpness which betokens a fitness for 

 market, but a very 'extensive deposit of protoplasmic matter which has been assimilated and laid 

 down mainly in the substance of the mantle. It is this relatively large amount of delicate, easily- 

 digested protoplasm, stored up in the palps and mantle, which renders the Oyster so wholesome 

 and nutritious. 



The deposition of this protoplasmic material in the mantle, palps, and body stands in intimate 

 relation to the activity of the reproductive organs. During the spawning season Oysters are said 

 to be " poor," that is to say poor in condition, for at this time the mantle, especially where it lies 

 next the body on each side, is very thin and quite transparent; the radiating pallial muscles along 

 the border of the mantle, as well as its vessels and nerves, may now be readily studied under the 

 microscope, owing to its transparency and the absence of opaque granular protoplasm. If we 

 examine the reproductive organs at this time, as a rule, we will find them greatly developed and 

 pouring out their products through two large ducts, the combined caliber of which is not far short 

 of that of the intestine. It will be evident to any thinking mind that if the major part of the food 

 material elaborated by the digestive and nutritive systems goes to the ovaries or testes to be 

 transformed into sex products, which are continually thrown off during the breeding season, little 

 of such material can be stored up in the tissues of the body. We have described exactly what 

 lisippens. In the mouth of September, when the Oysters in this latitude are for the most part 

 lone spawning, the drain of elaborated material having ceased to flow from the openings of the 



