AURICULARIALES 



549 



before spores are produced on the lateral sterigmata, reminding one of 

 the conditions found in some smuts. In S. Michelianum (Kiihner, 1926) 

 the uninucleate basidiospores germinate with a short sterigma which 

 bears a secondary spore only slightly smaller than itself. This becomes 

 three to six septate and produces one to two very small, ellipsoidal conidia 

 from each cell. The binucleate basidiospores form a septum between the 

 nuclei then germinate as above. 



The morphological significance lies in the increasing differentiation 

 of the zeugites which, here for the first time in semiparasitic forms, attain 

 the height of development of teliospores. Consequently Cystobasidium 

 and Septobasidium form an important approach to the Uredinales. 



Conidial fructifications have only been observed in S. albidum from 

 the East Indies (Patouillard, 1913). The hyphal tips are differentiated 

 into hyaline, later colored oidia (Fig. 366, 1). 



Phleogenaceae. — As in the other families of the Auriculariales, this 

 family begins with gymnocarpous forms, although here the higher 



Fig. 367. — Stilbum vulgare. 1. Fructification. 2 to 7. Development of basidia. 

 Hoehneliomyces delectans. 8. First basidium appearing on conidial hyphae. C, conidium ; 

 B, basidium. 9, 10. Macro- and microconidia, the latter catenulate. 11. Germination 

 of basidiospore with short hyphae, producing catenulate microconidia. (1 X 33; 2 to 7 X 

 1,320; 8 to 11 X 330; after Juel, 1898, and Moller, 1895.) 



members are angiocarpous. The basidia arise irregularly within 

 definite layers which correspond to the gleba of the angiocarpous 

 Basidiomycetes. The basidia lack sterigmata. 



In Stilbum vulgare (Juel, 1898) the fructification is scarcely more 

 than a well-developed coremium, with the erect hyphae held together by 



