Centimeters 



50 



Figure 169. — Diagram of a setup for simultaneous recording of the rate of water transport and shell movements of the 

 oyster. A — vessel with oyster; B and C — small connecting vessels; D — frame of the dumping vessel; E — dumping 

 vessel; F — float; G — springboard to record each overturn of the dumping vessel; H — paraffined float; K — slow motion 

 kymograph; L — cap to close the connection between the two vessel; M — lever recording shell movement; N — lever 

 recording the dumping of water; O — overflow; P — sea-water supply; Q — constant level siphon; R — barrels; S — signal 

 magnet; T — electric time recorder; X, Y, W — tubes for taking samples of water; Z — overflow tube leading to dumping 

 vessel. Temperature recorder is not shown. 



iiiterviils. The supply of sea water is delivered to 

 the barrels R set on top of tlie stand, and the 

 ii\ erflow siphon Q keeps the water in the containers 

 at a coitstant level and insures a uniform rate of 

 deli\ery of water to the experimental tank A. 



The size and shape of the dumping vessel run 

 he modified to suit the purpose of the experiment 

 and to facilitate its operation. The capacity of 



the dumping vessels made in my laboratory at 

 Woods Hole varied from 55 ml. to 226 ml. The 

 methods described above were successfully used in 

 a number of investigations (GaltsofI, Prytherch, 

 Smith, and Koehring, 1935; Chipnum and Galtsoff, 

 1949a, 1949b). 



All dumping vessels require frequent adjust- 

 ments and become unreliable if used continuously 



188 



FISH AND WILDLIFE SERVICE 



