120 



THE LOWER FUNGI— PHYCOMYCETES 



2. Myzocytium Schenk (tJber das Vorkommen Kontraktiler 

 Zellen in Pflanzenreich, p. 70, 1858), 



The mature thallus in this genus corresponds rather closely in 

 form with that of Achlyogeton, consisting, as there, of a simple 

 unbranched tube. Transverse septation results in the formation 

 of a row of more or less bead-like cells, as many as ten being 

 formed in a single thallus. Rarely reduced non-septate thalli 



Fig. 44.- — (a-c) Myzocytium proliferum Schenk in Spirogyra. (o) Different 

 cells of a single thallus functioning as sporangia and sex cells. (6) Chain of 

 sporangia, (c) Swarmsporo. (d) My. vcrmicolum (Zopf) Fischer in Anguillula. 

 {After Zopf I884.) 



occur which may be easily confused with those of Olpidium. A 

 reduced two-celled thallus was misunderstood by Sorokin, and 

 made the basis of his genus Bicricium. The cells of the thallus 

 in Myzocytium function either as sporangia or sexual cells. In 

 the latter case contiguous cells of the thallus usually function 

 as oogonium and antheridium, since the species are almost exclu- 

 sively homothalhc. Following fertilization a spherical thick- 

 walled resting spore ("oospore") is formed, and at maturity 

 lies free in the oogonium. After hibernation it germinates by 



