184 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



— 3*/; - 



Entire lank, excluding tubing, mode of Ve cellulose nitro**. 



Section through "A"' 



Section through *C* 



Scole in Inches 



t-— 2 Ve*-J 



Section through 



 HO i £ 3 



EXPERIMENTAL TANK USED IN MEASURING PUMPING RATE OF OYSTERS 



Figure A-l. — Tank used in the experimental study of oysters. The oyster is fastened to the Hopkin's stand with beeswax 

 at the ends of the small glass tubes. The water level at the top of the standpipe is finely adjusted so as to break over 

 with the addition of two or three drops of water, yet not back the water into the tank body. The tube is cut with a 

 carborundum saw and, once set up, it is never allowed to become dry, because the wetting property of the bacterial 

 slime which accumulates there would be destroyed and the "sensitivity" of the tube lost. 



