22 



I am now going to treat in short the arguments of Brandt. 

 In the following points he gives the chief differences between 

 chlorophyll corpuscles and algae: 



chlorophyll corpuscles 

 parts of cells 

 consisting of groundsubst. -|" 



chlorophyll 

 never a nucleus present 

 no cellulose membrane 

 not able to live by themselves 



algae 

 cells by themselves 

 consisting of chlorophyll -]- un- 



coloured protoplasm, 

 always a nucleus present 

 generally a cellulose membrane 

 able to live by themselves 



Then Brandt examines, which of these two series may be 

 applied to the chlorophyll of the Spongillidae (and of the other 

 chloropliyll containing animals). That is to say, he extensively 

 discusses the investigation of Hydra viridis, and for Spongilla 

 he refers to the results obtained in Hydra; in his way however, 

 it remains somewhat doubtful what Brandt exactly stated for 

 Spongilla. For the corpuscles of Spongilla he especially de- 

 scribes: 1. Generally a through-shaped chloroplast and hyaline pro- 

 toplasm. 2. A nucleus, that could be recognized very distinctly 

 by means of haematoxylin or magdala. 3. A diameter of 1.5 — 3jC4. 

 4. After having been isolated from the sponge-cells, they re- 

 mained normal and alive for 3—4 weeks. 5. Sometimes they then 

 seemed to have multiplied (but this required closer examination). 

 6. Green corpuscles of Spongilla, added to a culture of unco- 

 loured specimina of Stentor coeruleus were ingested by these, 

 but not digested nor ejected ; so it proved to be possible to graft 

 these corpuscles. 



I have some remarks on these points : 1. The nucleus. As said 

 before, Brandt discusses Spongilla very briefly only and for de- 

 tails he refers to the description of Hydra. In that description 

 is mentioned, that in all corpuscles (after having been stained 

 with haematoxyline) one or two, sometimes more, violet, round 

 or somewhat irregular spots could be distinguished; Brandt 

 declares them to be nuclei. They were solid corpuscles, but their 



