Classification . 147 



FaM. 5. CflYTRIDE^. 



The present family iRcludes a naraber of mostly 

 very minute parasitic or saprophytic microscopic 

 fiingi^ tlie greater part of which are aquatic or spend 

 at least a portion of their vegetative period in water. 

 A common point of agreement is the formation of 

 sporangia of characteristic forms, the contents of * 

 which break up simultaneously into zoogonidia or 

 swarmspores. Each zoogonidium has usually one 

 cilium, and produces either directly after con- 

 jugating in pairs fresh sporangia, or becomes covered 

 with a thick wall and forms a resting-spore, the 

 contents eventually becoming transformed into a 

 sporangium containing zoogonidia. The zoogonidia 

 escape from the sporangium through a narrow 

 opening, usually at the apex of the sporangium, 

 formed by the sudden swelling and melting of a 

 portion of the sporaugial-wall, and in some species are 

 at first involved in mucilage from which they extricate 

 themselves one by one, in other species they leave the 

 sporangium singl3^ The lite-history of one species, 

 described by Nowakowski, is summarized as follows 

 by De Baiy :^ — • 



" PolypJoagus euglen^e a parasite upon resting 

 Euglena virdis, has become the best known of the 

 Chytridieae through Nowakowski's beautiful investi- 

 gations. The swarmspore, when it has come to rest in 

 the water, becomes spherical in shape, and at once 

 puts out hair-like tubular-rhizoid processes in in- 

 definite directions (B). If one of these encounters a 



3 I.e. pp. 16-2-164. 

 L 2 



