ing. They have a single membrane, and are a 

 little diffuse, but, more often than not, a section 

 through a cell looks like this. 



GRUN: Yes, and there were others that 

 seemed to have a small drop. 



LOVETT: I'm not sure what you mean. 

 There are other granules. 



GRUN: They're similar to amyloplasts. 



LOVETT: There are other granules that 

 are polysaccharide, I'm sure. Ed's done the 

 work on polysaccharides. We haven't. The other 

 granules you see in between the lipid granules 

 in the side body are, I am quite sure, polysac- 

 charide. They stain with the PAS reagent. 



DEERING: I'm still after the answer to a 

 question that I asked earlier. There seems to 

 be a conflict in what you said with regard to 

 the spore development and the later picture 

 that you drew on the OC sporangium. 



LOVETT: Do you mean the basal cell? 



CANTESrO: Well, the basal part is just 

 rhizoids at the germling stage. 



DEERING: I'm trying to find out whether 

 or not it is a separate cell that makes rhizoids. 

 What about the basal cell and rhizoid formation? 



LOVETT: The basal cell occurs about the 

 same time the papillae form, I would say. Isn't 

 that right, Ed? 



DEERING: It's very late in development? 



LOVETT: Yes, and it is so obscure that it 

 is sometimes almost impossible to see without 

 very careful microscopic examination. 



DEERING: Sometimes if you look at these 

 in earlier stages, you can see what looks like 

 a small ridge. 



LOVETT: However, you don't see that until 

 they're really ready to go. Frequently, the basal 

 cell is so small, if it is there at all, that you 

 can't see it. You just see the rhizoids. 



DEERING: Is this basal "cell" separated 

 from the rest of it in electron micrographs? 



LOVETT: Give me about six or eight 

 months and I'll be able to tell you. We are 

 going to look at these stages in the electron 

 microscope, but we haven't done it yet. 



GROSS: Are there any nuclei in that lower 

 cell? 



LOVETT: In the RS form, the lower cell 

 forms at the time when everything is moving 

 out. In the OC, I don't think we could say one 

 way or the other, but probably not. These 

 plants, after all, are converting all their proto- 

 plast into spores. When the spores are gone, 

 there is no reason to leave anything behind, be- 

 cause the plant is dead. It's an empty hull. 



CANTING: That cross wall is laid down, 

 centripetally, from outward to inward, and as 

 that happens, what little protoplasm is down 

 there migrates upward and you're left with 

 an empty cell; at least, we call it a cell a la 

 Robert Hooke. 



GROSS: That is a bit confusing because it 

 doesn't sound like a cell at all. 



C ANTING: It's a compartment, a separate 

 compartment. 



LOVETT: It is very striking in the resistant 

 sporangium where it forms a big stalk. You can 

 almost watch the material move out of the lower 

 part. 



References 



1. E. C. Cantino. This symposium, (1966). 



2. B. Blondel and G. Turian. J. Biophys. Bio- 

 chem. Cytol. 7, 127 (1960). 



3. J. S. Lovett. J. Bacterial. 85, 1235 (1963). 



4. Sister M. N. Murphy and J. S. Lovett. De- 

 velop. Biol,, in press. 



5. R. P. Perry, P. R. Srinivasan and D. E. 

 Kelly. Science 145, 504 (1964). 



6. B. Wright. This symposium (1966). 



7. G. Turian. Protoplasma 54, 323 (1962). 



8. R. Munier and G. N. Cohen. Biochim. Bio- 

 phys. Acta 31, 378 (1959). 



9. P. R. Gross. This symposium, (1966). 



181 



