176 THE BIOLOGY OF HYDRA : 1961 



cally? If so, there is no need to replace the nematocysts along 

 the length of the tentacle. 



LANE: I think this is entirely possible. 



CROW ELL : Two other possibilities are that nematocysts are made 

 all along the tentacles, and that they are built back in headquarters 

 and are transported to the tentacles by unknown means. 



LENHOFF: In the chromatograms you showed, were you run- 

 ning the entire fluid or a hydrolyzate of the fluid? 



LANE: This was the entire material. We took the entire gastro- 

 vascular fluid without any treatment. I suspect we have amino 

 acids and peptides. We are now analyzing this fluid using paper 

 electrophoresis. 



LENHOFF : What was the solvent? 



LANE : n-propanol. 



LENHOFF: In H. littoralis we find that the gastrodermis takes up 

 mostly particles, and leaves behind the free amino acids in the 

 gut. Your chromatogram looks somewhat like a normal pattern 

 of free amino acids. Do you think Physalia does the same thing? 



LANE: We'll know more about this very soon. We find that toxin 

 peptides distribute very much like this and we have eluted, hydro- 

 lyzed, and rechromatographed them separately. We know they are 

 peptides. So without actually having done it on this gastrovas- 

 cular material, I feel fairly certain that these are peptides also. 



WOOD: Do you have any real evidence that the gastrodermis 

 extrudes materials into the mesogleal extracellular space, which 

 are then picked up by the epidermal cells? I question this because 

 it seems to me that it would be more efficient to transfer such 

 materials directly. This bears on whether your specialized area 

 in the mesoglea is cellular or is purely connective tissue? 



LANE: That was the way we had interpreted it, but this is 

 purely tentative and subject to change. Having seen the way in 

 which both endodermal and ectodermal processes interdigitate and 

 weave their way through the mesoglea in hydra, we could easily 



