DEVELOPMENT OF PLANTS 



213 



FIG. 127. Features in the reproduction of Polysiphonia: A, branch of 

 the plant bearing clusters of male gametangia, an. B, one of the clusters 

 enlarged, showing the numerous small gametangia. C, branch on which the 

 spores derived from the gametospores are enveloped by a sac. From one 



of these bodies, called cystocarps, the spores are escaping. 



* 



of the plant, or they may be associated in conspicuous groups. 

 The spores escape from the mother cell as naked bodies and 



FIG. 128. A branching filament of Cattithamnion, showing the spore 

 mother cells forming tetraspores. 



