EEPOET OF COMMISSIONEE OF FISH AND FISHERIES. XCI 



ably the most noteworthy contribution to the literature of the anatomy 

 of 0. edulis which has appeared in Europe for thirty years past is a 

 paper entitled "De Yoortplantingsorganen van de Oester, Bijdrage tot 

 de keunis van hun bouw en functie," by Dr. P. P. 0. Hoek, and illus- 

 trated by six well-executed lithographic plates. This paper, published 

 in the Journal de la Societe N^derlandaise de Zoologie (Liv. I, 1883), 

 gives for the first time a fully illustrated description in Dutch and 

 French of the organs of Bojanus of 0. edulis. 



The same paper also contains the most complete bibliography extant 

 of works relating to the oyster and oyster culture, which may be con- 

 sulted by those interested, with the assurance that about all that has 

 been written upon the subject up to within the last two or three years 

 has been noticed. 



Professor Horst, of the Dutch commission, has also made some im- 

 portant investigations upon the early stages of development of Ostrea 

 edulis, in which he has indicated the true nature of the gastrula stage 

 of this mollusk and the mode in which the supraesophagal ganglion 

 is developed. 



During the same period the Frencb naturalists have also been very 

 acti\'e, notably G. Bouchon-Brandley and Adrien Certes. The former 

 of these was the first to introduce a successful method of rearing the 

 spat of the dioecious 0. angulata from artificially impregnated eggs at 

 Verdon, in inclosed ponds, in 1882, though constant daily tidal action 

 was not permitted to effect the change of the water in the ponds as in 

 the American experiments with the eggs of 0. virginica instituted by 

 Mr. Eyder. 



American investigators have been no less active than their foreign 

 brethren. Prof. W. K. Brooks and Lieutenant Winslow — the first as 

 the biological editor of the report of the oyster commission of the State 

 of Maryland, and the latter in his elaborate investigations upon the 

 distribution, area, and condition of the oyster beds of the Eastern 

 United States — have contributed mucb valuable information upon the 

 subject of the oyster industry of America. 



Dr. W. M. Hudson and Hon. Eobert G. Pike also deserve particular 

 mention here in connection with their effective efforts in improving the 

 condition of the oyster beds under the jurisdiction of the State of Con- 

 necticut. 



Mr. J, A. Eyder, of the TJ. S. Fish Commission, has also been active 

 in contributing towards a knowledge of the life-history of the American 

 oyster. His experiments and investigations have covered a large range 

 of work upon the anatomy, histology, and physiology of the animal. 

 Among the most important of his researches are as follows: Those 

 which have determined the true nature of the " greening of oysters," 

 the absorption of pliycocyanin from the diatoms swallowed as food, and 

 its retention by the colorless blood corpuscles of the animal; the 

 structure of the gills, circulatory system, and reproductive and excre- 



