49 



black ooze, the very tissues seeming to be impregnated 

 with the color, the stomach and intestine loaded to en- 

 gorgement with the mnd, the animal manifesting every 

 sign of being in a decidedly sickened condition. The 

 cause of this was pi^obably that the shell with its tenant 

 had sunken too deeply into the mud when the ingestion 

 of the black ooze commenced, giving rise to the remark- 

 able changes which I have recorded. No doubt had this 

 condition of things persisted for long the animal would 

 have been smothered by the mud. 



MUD AND THE YOUNG FRY. 



The accumulation of the slightest quantity of sediment 

 around a young oyster would tend to impede its respira- 

 tion and in that way destroy it, yet, in the natural beds 

 there are so few naturally clean places which remain so, 

 that it is really surprising that so many young oysters 

 pass safely through the critical periods of their lives 

 without succumbing to the smothering effects of mud 

 and sediment. When it is borne in mind that at the 

 time the infant oyster settles down and fixes itself once 

 and for all time to one place from which it has no power 

 to move itself, it measures at the utmost one-eightieth 

 (1-80) of an inch, it will not be hard to understand hoAv 

 easily the little creature can be smothered even by a very 

 small pinch of dirt. The animal, small as it is, must al- 

 ready begin to breath just tn the same way as its parents 

 did before it. Like them its gills soon grow as little lil- 

 aments covered with cilia which cause a tiny current of 

 water to pass in and out of the shell. The reader's im- 

 agination may be here allowed to estimate the feeble 

 strength of that little current which is of such vital im- 

 portance to the tiny oyster, and the ease with Avhich it 

 may be stopped by a very slight accumulation of dirt. — 

 M()bius estimates that each oyster which is born has 

 ■n,';,-- of a chance to survive and reach adult ap:e, so nu- 



1,140,01 O / 



merous and effective are the adverse conditions which 



