EDWARD S. KLINE 157 



siderably less \isual tissue damage than is caused by the chemical 

 agents. As a result of the electric shock, significant numbers of 

 nematocysts are discharged and soluble material is released into 

 the culture medium; material which inhibits succinoxidase of mouse 

 liver (Table 4). The possibility exists that this procedure causes 

 the release of soluble material other than that from nematocysts. 

 A. similar way of causing nematocyst discharge has been reported 

 by Glaser and Sparrow ( ] ) . These workers also jDresented a pro- 

 cedure for the isolation of undischarged nematocysts from hydra 

 and other coelenterates. More recently Phillips (16, 17) and Lane 

 and Dodge (8) have presented procedures for the isolation of 

 undischarged nematocysts from Metridium and Physaha, respec- 

 tively. By modifications of their methods we are now able to collect 

 undischarged nematocysts from Hydra littoralis and hope to study 

 these soon. 



We purified the inhibitor ( Table 5 ) and attempted to learn some- 

 thing of its nature. The purified inhibitor is a macromolecule 

 which appears as a slow-moving and apparently rapidly diffusing 

 single peak in the ultracentrif uge ( Fig. 1 ) . Ultracentrifuge experi- 



TABLE 4 



Succinoxidase inhibition by material discharged from nematocysts by 

 electric current (from ref. 6) 



Inhibition of 

 Material enzyme activity 



Mouse liver homogenate plus Hydra medium 



before electric shock (0.4 ml.) 2 



Mouse liver homogenate plus Hydra medium 



after electric shock ( 0.4 ml. ) 27 



There were 57 animals in 2.5 ml. of solution. Aliquots of the solution without 

 Hydra were removed before the shock. The solution was then diluted to the original 

 volume and a shock from a 45-volt dry cell battery was applied. Then another aliquot 

 of the solution was removed. For the succinoxidase assay of 0.1 ml. of a 5% liver 

 homogenate was used in tlie reaction vessel. Q02 ( wet weight ) of control liver = 25. 

 The same overall effect can be repeated but the actual precentage of inhibition does 

 vary, depending upon differences in experimental conditions, e.g., the time the shock 

 is applied and the number of nematocysts that are discharged. 



