ORDER CHYTRIDIALES 



67 



k 



Fig. 20. Chytridiales, Family Physodermataceae. Urophlyctis alfalfae Magn. (A) 

 Rhizomycelium, "Sammelzellen," and resting sporangia. (B) Top view of resting 

 sporangium, (After Jones and Drechsler: J. Agr. Research, 20(4):295-324.) 



bifiagellate, one flagellum being very short, and that they are of two 

 sizes. These conjugate before infection takes place. This needs confirma- 

 tion as there is a possibiHty that these supposed zoospores or gametes 

 may have been organisms parasitic within the resting sporangia of the 

 Urophlyctis. Several species of Urophlyctis are known. (F'ig. 20.) 



As a tentative addition to the operculate Chytridiaceae, Tetrachytrium 

 and Zygochytrium, reported by Sorokin (1874) from Russia may be con- 

 sidered here for want of further information. They are soil or water fungi, 



