B 



/»"Ah7-^ <■ -- 



iV:-' •■vflr / V..---.. •:(••••" y _.' 



\: 



Fig. 122 Porphyridium cruentum. A-E, stages in nuclear and cell 



division ( x 1280). F, cells connected by stalks after division 



( X 1280). (After Zirkle and Lewis.) 



Fig. 123 Porphyra. A, thallus ( x J). B, attachment disk with three 

 primary blades and four (1-4) secondary. C, formation of carpo- 

 spores. D-H, formation of spermatia in P. tenera. (A, D-H, after 



Ishikawa; B, C, after Grubb.) 



224 



