768 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [6] 



four to five days and then died. Many, in fact the majority, of the sur- 

 vivors were more or less diseased, showing vesicular protuberances 

 from the surface of the body and slow and abnormal movements of the 

 cilia, with a tendency to develop and trail a slimy thread-like aj)pen- 

 dage after them to which various foreign bodies would adhere and im- 

 pede the free movements of the infantile oysters. This slimy thread 

 I regarded as a product of retrogressive development, perhaps, indeed, 

 of incipient putrefactive or disorganizing changes. The 15th and 16th 

 days of July were employed in following up the development of the lots 

 of eggs which had been fertilized before those dates. 



July 17. — Another lot of eggs were impregnated this day at 10.30 a. 

 m., an entirely new method being employed in the operation. The eggs 

 and spermatozoa were in fact squeezed from the animals with the end 

 of a smooth, slightly curved pipette; the latter, which was provided 

 with a collapsible rubber bulb at toi), was also used to lift up the gen- 

 erative products and transfer them to the dishes in which they were 

 fertilized. The pressure of the side of the pipette was applied progres- 

 sively along the oviducts, which open and pour out their contents uni- 

 formly at one point on either side of the body. In this way I find that 

 I get quite as many eggs as by chopping up tbe visceral mass, and with- 

 out contaminating the emulsion of eggs and spermatozoa with fragments 

 of the other tissues of the body. Temperature of the water to-day fell 

 from 840 F. to 70° F. 



My success in taking the eggs and spermatozoa by pressure upon the 

 generative organs and ducts led me to think of applying a similar method 

 of investigation to the removal of the contents of the stomach. A short 

 pipette or medicine dropper with a collapsible bulb compressible between 

 the thumb and forefinger was used. The nozzle of the pipette was in- 

 serted hito the mouth and through the gullet into the stomach, when 

 the contents of the latter may be drawn into the pipette by relaxing 

 the pressure of the thumb and finger upon the bulb. If carefully done 

 no extraneous matters will be taken into the i)ipette ; absolutely nothing 

 except the contents of the stomach will be removed in the operation 

 just described. In a lot examined this morning, I find grains of pine 

 pollen from the neighboring trees, empty frustules of diatoms of various 

 species, and a considerable number of large, brown, boat-shaped ones 

 with the brown endochrome still in them. Many of these were still 

 alive and exhibited their singular and characteristic movement in right 

 lines. A great amount of organic slime and debris of organisms was 

 also noticed, but these fragments of the soft parts of organic bodies in 

 most cases were not in a suflQciently good state of preservation to enable 

 one to identify them. As a whole, the slimy contents of the stomach 

 were greenish, the color being due to at least two causes — the color of 

 the biliary secretion, and the microscopic particles of food. 



The sexes of the oyster may be readily made out by the peculiar 

 characters of diffusibility proper to each kind of product when dropped 



