188 



C. M. CHILD. 



similar to those occurring in open dishes. More or less reduction 

 and disintegration of hydranths and development of stolons 

 occurs. Figure 1 1 shows the apical region of a stem in which the 

 original terminal hydranth has reduced tentacles with disinte- 

 grating tips and the subapical hydranth bud has advanced but 



little during the forty-eight hours since collection. Below the 

 bud two stolons have developed. In some other pieces in the 

 same dish most or all hydranths appear intact, and no stolons or 

 very few, chiefly in basal regions, are present. In still others 

 apical hydranths are already completely disintegrated and stolons 

 are growing rapidly. 



In all cases in standing water the original hydranths disappear 

 sooner or later and stolons develop, but a second and even a 

 third generation of hydranths may arise. After a week or ten 

 days, however, hydranths are usually entirely absent and all 

 tips have either given rise to stolons or the ccenosarc is retracted. 

 In short, the effect of standing water is essentiality the same as 

 that of the inhibiting agents, but less rapid. It is probably due 

 in large part to accumulation of CO2- There is always a decrease 

 in pH in the dishes containing the pieces, often to 7.5 or 7.4 in 

 the course of a week or less. 



TRANSFORMATION IN Gonothyrcea 



Gonothyrcea is much less susceptible to inhibiting agents and 

 to standing water than Bougainvillea. The hydranths survive 

 for several days or even a week under conditions which kill the 

 hydranths of Bougainvillea in a day or two. 



