PORPHYRIDIUM CRUENTUM NAEGELI 
339 
tion of Porphyridium must be uncertain until more is known of the nuclear 
history of the Bangiaceae. The resting stage is certainly unlike anything 
known in the Myxophyceae, though the later stages show a certain re- 
semblance to this group. The whole process is a bit too primitive for the 
Chlorophyceae. In regard to its other characteristics Porphyridium re- 
sembles the Bangiaceae, and it would be best to keep it in this group. 
The authors wish to thank Dr. W. R. Taylor for the material he supplied. 
Summary 
1. Divergent results of the various investigators are probably due to 
their working with plants at different stages of growth rather than to their 
working on plants of different species. 
2. The jelly is homogeneous only after a prolonged period of inactivity 
of the plant. In growing material the cells are born on gelatinous stalks. 
3. The chromatophore is star-shaped only in the resting stages. Its 
red coloring matter can be extracted, leaving it green. 
4. Porphyridium has a distinct, easily stainable, centrally located 
pyrenoid, which is generally spheroidal though sometimes ring-shaped. 
5. In the resting stage Porphyridium has a single eccentric globule of 
chromatin homologous to a nucleus or nucleolus. Nuclear division is 
crudely mitotic. 
6. Porphyridium had best be kept in the Bangiaceae at present. 
Biological Laboratory, 
University of Virginia 
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