21 



is green, imparting its own green color to the iinids and 

 thus to the tissues of such oysters as may be so situated 

 as to readily feed upon it. A recent writer^ gives an 

 account of some experiments made by M. Puysegur of 

 Sissable in artificially producing this green color, from 

 which I quote : ' ' In each plate, [lilled with water charged 

 " with green diatoms,] according to its size, we put three 

 " to six perfectly white oysters which had never been in 

 " the 'clears' and the shells of which had been previously 

 ^'washed and brushed clean. In similar plates like num- 

 "bers of the same oysters were laid in ordinary sea- 

 '' water. Twenty-six hours after the commencement of 

 ^' the experiment the oysters in the water charged with 

 ^' diatoms had all acquired a marked greenish hue ; the 

 " other oysters remained unaltered. -x- ^- ^ * 

 "After the oyster had turned green, it was laid in ordi- 

 "nary sea- water for a few days, when the greenness dis- 

 ' ' appeared altogether. It reappeared when the oyster 

 " was replaced in fresh water containing Namciila ostre- 

 " aria.^^ M. Decaisne, of the Jar din des Plantes^ Paris, 

 repeated the experiments with the same results. 



Besides the diatoms, the spores of algae, the larvae or 

 young of many animals, such as Sponges, Bryozoa. Hy- 

 droids. Worms, Mollusks, many of which are small 

 enough to be taken in by the oyster, though their bodies 

 in most cases being soft and without a skeleton, it is 

 impossible to hnd any traces, either in the stomach or 

 intestine, of their remains, to indicate that they have 

 formed a part of the bill of fare of the aniuial. What, 

 however, demonstrates that such small larval organisms 

 do help to feed the oyster, is the fact that, at the heads 

 of the small inlets or creeks along the Chesapeake, where 

 the water is but little affected by the tides and is some- 

 what brackish and inclined to be stagnant, there always 

 appears to be a relatively greater development of a some- 



*The green color of Oysters, H. M. C. In Nature, Vol XXll, 549 — 50, 1880. Trans. 

 from the Revue Maritime et Coloniale, February, iSgc. 



