BERNARD L. STREHLER 389 



(31). Some of these are shown in Tables 1 and 2. One of the things 

 that we measured was the efficiency of catching Artemia. This did 

 not seem to be altered between one and five days of age, which is 

 about the greatest longevity of appreciable numbers of hydranths in 

 Woods Hole at 17-18 . Similarly, the digestion time was measured 

 by feeding fluorescent labeled Aiiemia to Camponularia and then 

 measuring the time required for the first fluorescent digest to appear 

 in the region proximal to the hydranth (see Fig. 14). As measured 

 in this way, no differences between young and old were observable. 

 Neither did the egestion time nor the maximum number of Artemia 

 the hydranths can consume change with age. 



In short, the only striking differences we have found between 

 young and old CampanuJaria, other than the above-mentioned acid 



TABLE 3 



ATP content/hydranth vs. age 



Stage ATP/hydranth = (g X 10'") 



Hydranth bud 15.0 



Early differentiation 7.0 



Complete differentiation but not extended 33.0 



1 day old (young) 18.0 



2-3 days old (middle-aged) 12.0 



4-5 days old (old) 4.5 



phosphatase accumulation, is a difference in the level of the adeno- 

 sine triphosphate as measured by our firefly enzyme ATP assay 

 method. We observed a decrease to about one-third of the total 

 ATP level in passing from one to five days of age (see Table 3). 

 This value was calculated per hydranth rather than on a dry weight 

 basis and we do not know whether there is a change in the dry 

 weight of Campainiknia during this time interval. We can thus not 

 say whether this ATP concentration drop is due to a decrease in 

 the intracellular concentration or volume. 



Complete lack of oxygen for a period of several hours does not 

 produce degeneration of Campanidaria, although we have obtained 

 evidence from time lapse studies that partial anaerobiosis can rapidly 

 induce degeneration. During the complete absence of oxygen for 



