DEUTEROMYCETES 405 



Hymenium whitish, basidiamore or less curved, 1-3 septate, 

 each cell of the basidium bearing one spore ; spores elliptical, 

 curved, hyaline, 10-12 X 5-7 /*. 



Tanaka, Journ. Coll. Sri. Imp. Univ. Japan, 4, pt. i, p. 193, 

 pi. 24-27 (1891). 



DEUTEROMYCETES 



The members of the present group have of late years been 

 considered as representing conidial forms of higher fungi, 

 and in fact so many of these fungi have been definitely 

 proved, by means of carefully conducted pure cultures, to be 

 in reality phases in the life-cycle of fungi belonging to the 

 Ascomycetes and the Basidiomycetes respectively, that pro- 

 bably the supposition is quite correct. At present, however, 

 there are many thousands of forms included in the present 

 group that have not been actually proved to be connected 

 with any higher form, hence it is necessary in the meanwhile 

 to retain the names, if only as a matter of convenience, until 

 they are definitely proved to be stages only in the life-history 

 of other species. 



From an economic standpoint, the members comprising 

 the present group are perhaps more important than those 

 belonging to any other section of fungi, as it is almost invari- 

 ably the conidial or summer stage of a fungus that infects the 

 host and causes a wholesale epidemic. 



The Deuteromycetes are divided into three primary 

 groups : 



1. Sphaeropsidiaceae. Conidia produced in a definite peri- 

 thecium. 



2. Malanconiaceae. Perithecia absent j conidia borne on a 

 compact stroma or solid mass of hyphae that gives origin to 

 crowded conidiophores bearing the conidia at their tips. 



3. Hyphomycetaceae. Perithecia and stroma absent; coni- 

 diophores superficial, erect, often branched, and bearing the 

 conidia at the tips of the branchlets. 



Most of the species are quite minute, or, as usually termed, 

 microscopic, and are often recognised by the blotches they 

 form on leaves, fruit, etc., caused by the mycelium of the 

 fungus killing or injuring the tissues in the affected area, the 

 true fruit of the fungus appearing as minute dots or dark 

 coloured points on the injured patches. 



