10^ 



scribed on page G5 . In one instance, however, a xiiother 



y 

 cell was observed in ..hich no trace of cleavage of tlie c.t- 



toplasm was apparent, and in vJiich the niunber of nuclei had 



increased to^the whole structure resembling very much the 



early stages of germination of a normal spore. It seems 



quite possible that the tetraspore mother cells borne on 



the sexual plants sometimes germinate as monospores, though 



tliis can be ascertained only by cultivation. 



On the otlier hand, tetr^cporic plants may at times 

 produce structures morphologically identical with procarps. 

 Text-figure / is taken from a tetrasporic plant of Sper - 

 mothamnion Turneri collected at Wood's Hole in August, 

 1907, and shows tetr£tspores and procarp on opposite branch- 

 es of the same fil ament. Text-figure ^ shows a section 

 of the tetrasporangium in which the definitive tetraspores 

 are formed, though not yet separa^ted. Antheridia liave not 

 been reported as occurring on Spermo tharoni on Tiu'neri at 

 Wood's Hole, and cystocarps are very rarely produced. 

 Whether functional gametes are ever produced on an indi- 

 vidual v;hich bears normal tetraspores is not known. 



Another species of Sp ei^mo t hamn ion . S. roseolum , is 

 extremely interesting from our point 5?f viev/. pRINGSIffilM 

 states that in this species, which he collected on the 



