■40 A NEW METHOD FOR GROWING HYDROIDS IN SMALL AQUARIA 



A tall bell-jar was used, about 20 inches (50 cm.) in height and 

 8 inches (20 cm.) in diameter. The top of the tube A was about 



-G 



Fig. 1. 

 Diagram of the current-tvibe inside a bell-jar. 



9 inches (23 cm.) below the surface of the water, which was about an 

 inch below the top of the bell-jar. 



After adjusting the current-tube, fill the bell-jar with sea-water, 

 and connect tube E at F, with rubber-tubing, to the pipe G, supplying 



