CONJUGATING FUNGI— PHYCOMYCETES 



237 



smooth, slightly coloured, but their ultimate history and 

 development are still rather obscure. 1 



By comparison of this family with the preceding it will be 

 observed that whilst the gonidial reproduction resembles most 

 that of the Peronosporaceae, it is by no means the same : the 

 gonidiophores are less highly developed, and active gonidia, or 

 zoogonidia, would seem to be absent. The conjugation also 

 differs from that of all the other families, and approaches more 

 closely to that of the Algoid type, as represented by some of 

 the filamentous Gonjugatae. 



From this summary of the main features of the four 

 normal families, we must turn to the 

 two remaining families, which are so 

 far abnormal, or aberrant, as to be 

 deficient of conspicuous hyphae. The 

 Ghytridieae are mostly very minute, 

 and either parasitic or saprophytic, 

 forming sporangia of characteristic 

 forms, the contents breaking up into 

 swarm-spores. These zoogonidia, or 

 swarm-spores, escape from the spor- 

 angium, through a narrow opening, 

 usually at the apex. Nowakowski 2 

 has given the life -history of one 

 species, which is , parasitic upon 

 Uuglena. In this species of Poly- 

 phagus, the swarm-spore, when it has 

 come to rest in the water, becomes 

 spherical in shape, and at once puts 

 out hair-like, tubular rooting (rhizoid) processes in indefinite 

 directions. If one of these encounters a resting Uuglena 

 it penetrates into its body, destroying and exhausting 

 it to supply food to the parasite. The parasite then 

 begins to increase in size, the tubes become larger and 

 thicker, and new ones are formed which throw out branches, 

 and attack and destroy any new Euglenae which they encounter. 



1 Vegetable Wasps, etc., by M. C. Cooke, 1892, p. 10. 



2 Beiirag zur Kenntniss der Chytridiaceen, von Dr. L. Nowakowski, Breslau, 

 1876. 



FlQ. 114. — Conjugating hyphae 

 in Entomophthora, with 

 zygospores. After Thaxter. 



