CONJUGATING FUNGI— PHYCOMYCETES 239 



genus Synchytrium is provisionally included in this family, 

 although no sexual reproduction is known. When compared 

 with such families as the Mucoraceae and the Peronosporaceae, 

 the Chytridieae seem to have little in common, save the pheno- 

 menon of conjugation, and appear to be, in fact, in conjunction 

 with Protomyceteae, an outside group, of doubtful natural 

 affinity. 



In the Protomyceteae the mycelium is very fugitive, at first 

 seated in the tissues of the plants upon which the species are 

 parasitic, and then septate, contrary to the usual condition in 

 the Phycomycetes. Conidia are unknown. The entire system 

 of reproduction consists in the development of thick-walled 

 resting spores. In germination the endospore escapes through 

 the rupture of the thick wall, in the form of a sporangium, 

 filled with minute, motionless spores, which conjugate in pairs. 

 After conjugation the spores germinate by emitting a slender 

 germ- tube, which enters the foster -plant, and produces a 

 mycelium, from which resting spores are developed, and the 

 cycle is complete. 



Strongly impressed with the absence of any true natural 

 affinity between the last two families and the four preceding 

 ones with which they have been associated, we have no alter- 

 native but to include them under protest, and to suggest that 

 the one fact of conjugation, as feebly carried out, is insufficient, 

 in the absence of other indications of relationship, to warrant 

 the retention of these two families with the Phycomycetes. As 

 evidence that their affinities have always been held in doubt, 

 it may be added that, until very recently, the genera Ohytridium 

 and Synchitrium have been included with Algae, 1 although 

 subject to the observation that " The genus Synchitrium 

 appears to be more nearly related to Protomyces, amongst 

 Fungi, than to Algae." Under any circumstances they can 

 only be regarded as aberrant families, mechanically and pro- 

 visionally tacked on at the end of this order, until they may 

 be assigned to a more fitting place. 



1 British Fresh Water Algae, by M. C. Cooke, 1884, p. 198. 



