148 



PHAEOPHYCEAE 



from each node. Unilocular sporangia, together with clavate 

 paraphyses, develop in sori, the sporangia arising from the base of 

 the sterile threads. The life cycle has not yet been worked out, but 

 if it is at all comparable with the other closely related genera then 

 the zooids should give rise to a microscopic gametophyte genera- 

 tion. 



Sporochnaceae : Sporochnus {sporo, seed; chnus, wool). Fig. 10 1. 



The thallus, which is composed of an inner layer of large cells 

 with an outer layer of small assimilatory cells, is filamentous with 



Fig. loi. Sporochnus pedunculatus. A, plant. B, fertile branch with receptacle. 

 s = sorus. C, unilocular sporangia (m). e = empty sporangium. (After Oltmanns.) 



branches arising alternately and arranged in one plane. On 

 account of its structure Church considered that it really belonged 

 to the parenchymatous type of construction, and morphologically it 



