CLASSIFICATION OF THE TRUE FUNGI. 109 



Families : Gasteromycetes, Hymenomycetes, Tremel- 

 lini, ^Ecidiaceae or Uredineae, Entomophtoreae, Ustila- 

 gineae. 



Third order: Zygomycetcs. These form zygospores, 

 as the highest form of fructification ; these spores arising 

 by copulation. A non-sexual formation of spores by 

 sporangia, or by separation of conidia, usually precedes 

 this fructification. 



Families : Mucorineae, Chaetocladiaceae, Piptocepha- 

 Iidea3. 



Fourth order : Phy corny cetes. These are unicellular 

 thallophytes. The cell is tubular, and forms the spores 

 at the end of some of its branches. In the non-sexual 

 fructification these spores are swarming spores or conidia; 

 oospores are also often formed. 



Families : Saprolegniaceae, Peronosporeae, Chytri- 

 diacese. 



Of the various orders and families mentioned, I Description of 

 have only selected for more detailed description those interesting* Y 

 which are of directly hygienic interest, in that they at fungi - 

 times appear as parasitic exciting agents of disease in 

 man and the higher animals ; or those which demand 

 attention on account of their wide distribution as ordinary 

 mould fungi, and on account of their constant occurrence 

 in all practical mycological work. In addition, some of 

 the forms which attack lower animals and plants are 

 described shortly where the mode of appearance and 

 distribution of the diseases excited by them furnish 

 analogies with human infective diseases. For all other 

 details the botanical text-books mentioned above must be 

 consulted. 



A. The following forms, which are parasitic on plants 

 or the lower animals, may be mentioned : 



1. Ustilagineae. The fungi of various forms of blight Blight fungi, 

 (order : Basidiosporeae). These are parasitic on the 

 organs of plants, especially on various kinds of grain. 

 The fine mycelium threads grow between and transversely 

 through the cells of the plants. At certain spots the 



