ANCYLISTALES 



127 



4. Mitochytrium Dangcard (1911: 200). 



This genus was erected on the single species, M. ramosum 

 Dang., found in the cells of Docidium, a desmid. The thallus, 

 as figured, resembles that of Lagenidium except that it is provided 

 at several points with finely branched rhizoids and is non-septate. 

 The form was inadequately discussed, but was regarded by Dan- 

 geard as intermediate between the Ancylistales and Chytridiales. , 



5. Protascus Dangeard (1906), not Protascus Wolk (1913). 

 This is a monotypic genus based on the single species, P. sub- 



idiformis Dang., parasitic in the body of Anguillulidae. The 



Fig. 48.- — Resticularia nodosa Dangeard in Lyngbia. (a) Thallus sending 

 branches outside of host. (6) Sporangium germinating. {c,d) Zygospore 

 formation. {After Dangeard 1890.) 



fungus resembles in general structure Myzocytium and Lageni- 

 dium but differs in several striking respects. The endozoic 

 thallus is septate at maturity into eight cells of similar aspect. 

 These fall apart at the septa, and may be termed segments. 

 They function as sporangia or gametangia. The number of 

 spores in the sporangium is extremely variable (approx. 8-200). 

 They pass through an exit tube to the surface of the host, and 

 are there apparently discharged with considerable violence. The 

 spore is non-motile and in form is clavate with the narrow end 

 tapering to a sharp point. Infection is accomplished when the 

 narrowed end of the spore attaches itself to the new host. Seg- 

 ments functioning as sporangia and gametangia may result from 



