Classification, \ 5 1 



Analysis of the Genera. 



A. Parasitic in Phanerogams. 



Synchytrium. Resting-spores formed in the epider- 

 mal cells. 



B. Parasites or saprophytes on algge^ ^^ngi^ or dead 

 animals, generally aquatic. 



Rhizidium. ConsistiDg of two superposed cells, the 

 lower producing rhizoids. 



Polypliagus. Parasitic on Eiiglense. 



Beessia. Zoogonidia conjugating in pairs and form- 

 ing resting-spores. 



Chytridium. Consisting of a single cell, the 

 sporangium, which is furnished with an elongated 

 operculate beak at the apex through which the zoo- 

 gonidia escape, and with rhizoids at the base. In the 

 cells of fresh-water algse. 



Olpidium. Consisting of a single cell, the sporan- 

 gium, furnished with a lengthened beak through 

 which the zoogonidia escape, rhizoids absent. 



Synchytrium, De Bary and Woronin. 



Minute unicellular fungi, entirely destitute of 

 mycelium, inhabiting the epidermal cells of living 

 plants ; reproduction by zocgonidia produced in 

 resting-spores or sori ; no sexual mode of reproduction 

 known. 



De Bary and Woronin, Ber. Nat. Ges. Frieb. iii. H. 

 ii. S. 22 ; Sacc. Syll. vii. pt. i. p. 288. 



A geous remarkable for the total absence of 

 mycelium. A zoogonidium penetrates an epidermal 

 cell of the host plant, where the protoplasm increases 

 considerably in size, causing the epidermal cell also to 

 increase in size and project above the surface like a 



