BULLETIN OF THE UNITED STATES FISH COMMISSION. 403 



random, opening the intestines under the microscope, and preserving 

 the contents either as microscope slides or in capillary vials, I found 

 that these ten specimens had eaten twenty-four entomostraca, all be- 

 longing to two species, descriptions of which I have in press, viz: 

 Cyclops thomasi and Diaptomus sicilis — fourteen of the first and ten of 

 the second. 



Besides these I found only a few diatoms (baccillaria) in two of the 

 fishes ; a little fragment of a filament of an alga in one, and three roti- 

 fers {Anurcca striata) in another. 



I will prepare a full account of the experiment, with a description of 

 the developmental conditions of the fishes when they commenced to eat, 

 and a full analysis of their food, as soon as I have time to do the work. 



I am indebted to Mr. Clark for the specimens; to the Chicago Expo- 

 sition Company for the use of the tank, and to the State of Illinois for 

 the expenses of the experiment. 



Illinois State Laboratory of Natural History, 



Normal, III., March 27, 188: 



■u. 



NOTES 0!V THE BREEOINC, FOOD, AKD OREEIV COI.OR OF Tri£ 



OY.STFR. 



By JOHIV A. RYDER. 



Xo mollusk known to the naturalists, it appears, is consumed in such 

 vast quantities as our native oyster, the Ostrea virginica of Gmelin; hence 

 its great economic importance antl the scientific interest which it has 

 recently awakened. It is vastly superior in flavor, size, and vigor of 

 growth to the oyster of Europe, and is simulated and approached only by 

 one old Continental form which I have seen, probably the Ostrea ros- 

 traJis of Lamarck. The first attempt made in the artificial impregnation 

 of the eggs of this noble mollusk was successful in the hands of our 

 countryman, Prof. W. K. Brooks, of Johns Hopkins University, of Balti- 

 more, who, in 1880, published a remarkable memoir on the subject in 

 the annual report of Maj. T. B. Ferguson, one of the fish commissioners 

 of Maryland. Professor Brooks' triumph was not, however, as complete 

 as might have been desired, since his investigations have not yet led 

 to the development of methods whereby the oyster could be propagated 

 by purely artificial means, but his success was so far beyond what was 

 attained by Dr. Davaine in his attempts at the artificial fertilization of the 

 European oyster in 18.51, that Brooks' achievement marks the most im- 

 portant era in the history of the subject. Others, as well as the writer, 

 have repeated his experiments with more or less success, and the latter 

 has been able to work out a portion of the developmental history of Mya 

 arenarla, clam or manauose, using artificially impregnated eggs for the 

 purpose, which were dealt with the same as those of the oyster. 



An earnest, and, it is to be hoped, successful etibrt is being made by 



