(58 



first attempt to artificially impregnate the eggs of the 

 European oyster, and as the inferences which can be log- 

 ically drawn from its success affect the theory of the 

 reproduction of the animal and the development of its 

 eggs to the same extent as those drawn from like suc- 

 cessful experiments affect our o^^^l species, I have 

 thought my work might prove both of interest and of 

 value. 



I labored under many disadvantages, and with a very 

 inferior ndcroscope, though magnifying 300 diameters, 

 of obsolete pattern, and at times had to contend with the 

 irregular motion of a vessel at sea and the deficient light 

 afforded by lamps. All my appliances were such as I 

 could obtain or improvise on board ship, and their rude- 

 ness and the inconvenience they caused hampered me a 

 good deal in conducting the experiment. I regret that 

 my observations were not more systematic, regular and 

 frequent, but a naval officer has but few moments which 

 he can safely call his own. and my official duties neces- 

 sarily compelled my frequent and prolonged absence 

 from the microscope. 



HISTOKY OF THE EXPERIMENT. 



The oysters were obtained from the mouth of St. Mary's 

 River, in the Bay of Cadiz, Spain, and were natives, the 

 variety having existed and flourished in the Bay for as 

 far back as could be remembered. In appearance they 

 were quite similar to the American species {Ostreoj mr- 

 ginmna)^ having long shells of from one to three inches 

 in length, rougher and thicker than is usually the case 

 with the Euroj)ean oyster ; there were no clusters how- 

 ever, all the animals growing- singly, and but a very few 

 young of the previous season were attached to the shells; 

 those noticed were probably nine or ten months old, and 

 though certainly of the brood of the previous season 

 were small sized when compared with the American oys- 

 ter of the same a.fi^e. The adults were about the size and 



