200 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



is impossible to start the larval shell of the oyster from its surface of 

 attachment, after it has acquired the umbones and before it begins to 

 develop the spat shell, without breaking it. This is proof that the shell 

 of the fry has been glued to its surface of attachment at a very early 

 stage; and it is also a fact that it is invariably the left valve which is 

 undermost with its beaks directed towards the left side. 



COMPARATIVE FREEDOM OF THE WATER FROM SUSPENDED MATTER. 



The northern waters where oysters are grown seem to be clearer and 

 less fall of suspended particles, at least in Buzzard's Bay, than in the 

 Chesapeake. This may be one reason why the spat catches in such 

 abundance in certain places, sticking to gravel, dead shells, bowlders, 

 stones, buoys, and all kinds of fixed objects having clean surfaces. It 

 may be that the water of the Chesapeake, holding more sediment in 

 suspension, is less favorable for the attachment of spat than that of the 

 clearer northern oyster regions. At any rate, the deposition of sedi- 

 ment at some places in the Chesapeake proceeds at an unusually rapid 

 rate, which would naturally, as explained above, interfere with the at- 

 tachment of the fry. This has suggested to the writer the practicability 

 of transporting small spat from the northern waters to the more south- 

 ern, inasmuch as it seems that a greater proportion of spat will catch 

 and grow on the same area there than in the south. Certain it is that 

 quite young spat may be transported, say from the Chesapeake to 

 Chincoteague Bay, and survive the journey and grow very rapidly, as I 

 had opportunity to learn during the past summer on the grounds of 

 Messrs. Pierce & Shepard. Whether it would be profitable to trans- 

 port small spat for long distances, and whether it would survive such a 

 journey could, of course, only be learned by actual experiment; but it 

 is possible that the experiment would be worth a trial. 



ABSORPTION OF BRACKISH WATER BY SALT-WATER OYSTERS. 

 The growers who carry on the cultivation of the oyster practic • in 

 many places what is called "plumping" or puffing up oysters Cor mar- 

 ket by exposing them for a short time to the effects of water fresher 

 than that in which they grew. One party at Franklin City has actu- 

 ally used steam heat in order to warm fresh water to 05° or 70° Fahr. 

 in winter, so as to get the oysters to open their valves and take in 

 enough fresh water to puff up their flesh and give them a better appear- 

 ance in the market. By this process the animal does not acquire any 

 additional matter except the water, which is taken up in great amount, 

 but it loses a part of its saltness, and, in flavor, becomes more like an 

 oyster from brackish waters. 



EFFECT OF SEA WATER ON BRACKISH-WATER OYSTERS. 



It is a remarkable fact that just the reverse effect will be produced 

 on the flesh of oysters which are carried from brackish into water which 

 is more salt. This was shown by taking some oysters from Buzzard's 



