CHARLES E. LANE 177 



expect the same thing to take place here. It may be that these 

 tremendously hypertrophied endodermal cells penetrate through the 

 mesoglea in these regions. 



MARTIN: I want to mention an experiment which supports 

 Dr. Lane's hypothesis. We didn't work with Phy.salia or hydra, 

 but with Anthopleura elcgantissima. We separated the tentacles 

 from the column and took the mesenteries out. Then we ground 

 up the column and tentacles separately, made extracts and mea- 

 sured their toxicity by injecting them into mice and we found that 

 the extracts of the nematocyst-poor column was as toxic as a 

 crown, which is nematocyst-rich. 



HAND: Did you remove the mesenterial filaments? 



MARTIN: Yes. 



HAND: Fine. 



MARTIN: By the way, the mesenteric filaments were less toxic 

 than the other two fractions. 



HAND: That's quite contrary to what I would have expected, 

 since they have the bulk of the internally located nematocysts. 



SLAUTTERBACK: There is a mesogleal formation in hydra 

 somewhat similar to the specialized areas you described. A great 

 accumulation of mesoglea is sometimes seen under the pedal disk 

 secretory cells. The predominant component here is amphorous. 

 Whether it is the same material commonly found in the mesoglea 

 has not been determined. The fine filaments and glycogen granules 

 are not increased as much. 



Also, is the greatly enlarged part of the hypertrophied gastro- 

 derm cells an enlarged "central vacuole "? 



LANE: Yes. 



SLAUTTERBACK: Were you ever able to fix anything in that 

 vacuole? 



LANE : We've tried a wide spectrum of fixatives on these vacuoles 

 but they've always been clear. 



BURNETT: Have you ever found nematocysts in the gastroder- 



