JOHN H. PHILLIPS 253 



being from the anemone. I think this proof must come from repeated 

 isolations, such as we carried out, and from a comparative study 

 of the morphology of the cells. Also a consideration of the cloning 

 efficiency assists in discarding the possibility that the cultured cell 

 is some parasite present in small numbers within the animal. 



WAINWRIGHT: Have you tried collagenase on the intercellular 

 material? 



PHILLIPS: No. Those are the only enzymes I have tried so far. 

 It is resistant to trypsin and hyaluronidase but degraded by lyso- 

 zyme. 



WOOD: I was not quite clear about your statements concerning 

 the mitochondria. Have you tried a specific mitochondrial staining 

 technique or do you have other criteria for identification? 



PHILLIPS: No. I simply said that they resembled mitochondria 

 in that they were markedly bar shaped. That's all. 



STREHLER: Is there only one morphological type of cell? 



PHILLIPS: One sees a variety of cell types in developing cul- 

 tures. For example, the ratio between nuclear and cytoplasmic size 

 varies as well as the distribution of the granules within the cells. At 

 the same time clone cultures derived from a single cell also shows 

 this variation. 



SLAUTTERBACK: If the anemone is anything like hydra, you 

 can determine whether or not they are gastroderm cells by expos- 

 ing the animal to a thorotrast solution for a short time. Thorium 

 dioxide serves as an excellent tag because only gastroderm cells 

 pinocytize it. 



WOOD: Could you be certain that free cells derived from ecto- 

 derm would not pinocytize or phagocytize some thorotrast? 



PHILLIPS: These cells do show a rapid uptake of such ma- 

 terials as bovine and human serum albumin. If one labels such 

 proteins with azo dyes within 15 minutes you get cells with 

 brightly stained inclusions and the cells remain colored for long 

 periods of time. In fact, it was in connection with immunological 

 studies that I first became interested in cultivating these cells. 



