5° AMERICAN FISHERIES SOCIETY. 



abundant secretion of mucous or " slime," so much, indeed, as 

 to sometimes render a small quantity of water in which the 

 animals may be confined, quite sensibly gelatinous. He sug- 

 gests that the change to fresh water may, indeed, induce such a 

 secretion of mucous and perhaps of carbohydrates and fats as 

 well, which would account for the increase of these substances 

 in the liquids. The observation of oyster dealers that water al- 

 ways thickens the natural juices that adhere to the surface of 

 the oyster and makes it slimy," accords with Prof. Conn's 

 statement. 



If such secretion did take place, the flesh must probably have 

 lost a little protein during the floating. The estimates of ab- 

 solute gain and loss of weight of flesh and ingredients (see de- 

 tailed accounts of the experiments) are based upon the assump- 

 tion that the quantity of protein was unaltered in floating. If 

 protein was given off, therefore, the estimates are wrong. But 

 the quantity of protein secreted and the consequent error must 

 be, at most, very slight. If there is an error its effect would be 

 to make the quantities of nutrients after floating appear larger 

 than they really were. In other words, if the error was cor- 

 rected it would make the loss of nutritive material in floating 

 greater than it appears to be in the figures above given. As ex- 

 plained in the detailed report above referred to, I have assumed 

 that the changes due to the ordinary processes of metabolism 

 would be too small to materially affect the results. 



The experiments might have been so conducted as to decide 

 this questi(jii. It would have been necessary to simply take a 

 larger number in each lot before and after floating and be cer- 

 tain that the number, weight, and bulk were the same in the 

 floated and not-floated lots of each experiment. For instance, 

 we might, in each experiment, carefully select two lots of, say 

 a bushel, each, as taken from the beds, have the number of oys- 

 ters the same in each bushel as an additional assurance that the 

 two lots were alike, float one bushel and weigh and analyze 

 both. A few experiments of this sort made under different con- 

 ditions of time, temperature, kind and age of oysters, &c., would 

 give reliable and valuable data. Unfortunately the means 

 at my disposal did not permit so thorough experiments. I am 



