48 



ganic debris, the former part of which is mainly derived 

 from the comminuted fragments of plants growing in the 

 creek. This seemed to be the true history indicated by 

 what was noticed in studying the box-collector. The 

 sam.e opinion is held as to the origin of this mud by both 

 Coste and Fraiche in their works on oyster-culture. 



There is probably no worse enemy of the oyster-cultur- 

 ist than this very mud or sediment. It accumulates on 

 the bottom of the oyster grounds, where in course of 

 time it may become deep enough to cause serious trouble. 

 Especially is this true of ponds from which the sea ebbs 

 and to which it flows through a narrow channel. The 

 falling leaves from neighboring trees in autumn also con- 

 tribute to this pollution as well as heavy rains which 

 wash deleterioiis materials into it. 



Adult oysters which are immersed in part in this mud 

 struggle hard to shut it out from their shells. If one 

 will notice the inside of the shells of oysters which have 

 grown in a muddy bottom, it will often be seen that there 

 are blister-like cavities around the edges of the valves 

 filled with mud, or a black material of a similar charac- 

 ter. There is not the slightest doubt in my mind that in 

 these cases the animal in order to keep out the intrud- 

 ing mud has had recourse to the only available means at 

 its command. A great many of the oysters in the pond 

 are affected in this manner, but it is extremely uncom- 

 mon to find shells of this kind in opening oysters coming 

 from a hard bottom. It is easy to understand that such 

 efforts at keeping out the mud from the shell Avill not 

 only waste the life forces of tlie animal but also tend to 

 greatly interfere with its grov\-th. The importance, 

 therefore, of artificial prei:>aration is apparent, Avliere it 

 is desirable to establish ponds for the successful culture 

 of this mollusk. 



Only in one case have I observed that the mud tended 

 t(^ impair the flavor and color of the oyster. In tliis in- 

 stance the animal was thoroughly saturated with the 



