CHARLES E. LANE 



171 



l4» 



Fig. 2. Frontal Section through the fishing tentacle of Physalia X 200. 

 The gastrovascular cavity of the tentacle communicates in the center of the 

 field with the cavity of a single "battery." Hypertrophy of the gastrodermis 

 begins at the equator of the battery. 



capsule and coils in the same clock-wise direction in approximately 

 the same plane. 



If the surviving tentacle be stimulated by gradually increasing 

 the concentration of solutes in the surrounding water, the nema- 

 tocysts may be made to discharge. This is a dramatic, explosive 

 process, the nematocyst threads being hurled from the capsule 

 with sufficient force to penetrate the surface film. This observation 

 explains our early experience of being severely stung even through 

 a surgical glove. 



In our laboratory we isolate surviving nematocysts by con- 

 trolled autolysis at 4", followed by screening, sieving, washing, 

 and settling. The washing process is continued until the wash 

 water is no longer toxic when injected into the hemocoele of the 

 fiddler crab. This point may acquire some significance when one 

 attempts to compare the activity and biochemistry of the toxin 



