AURIC ULARI ALES 



547 



pyriform outgrowths, which bend down on account of their weight (Fig. 

 364, 11 and 12, A). During the development of the basidium, the content 

 of this sac passes into it, whereupon the basidium is abjointed and 

 forms basidiospores. As in Iola, the subterminal cell develops a new pro- 

 basidium. The basidiospores develop, with or without previous septa- 

 tion, to secondary spores or form a gelatinous mass of small conidia, 

 surrounded by a viscid gel (Fig. 364, 13). A cytological study of this 

 species is needed for the interpretation of this storage organ which is 

 unknown in other groups of fungi. 



Septobasidium also lacks the gel, and shows an increasing differentia- 

 tion of zeugites. It is chiefly a tropical genus, although a few species 



Fig. 365. — Septobasidium bogoriense. A. Section of outer growth zone of crust. B. 

 Hyphae developing pillars. C. Section of mature crust, stimulated by particles of earth 

 to new growth. (X 110; after Gaumann, 1922.) 



occur as far north as southern Canada. As far as they are known, they 

 grow either saprophytically or epiphytically on the secretions of scale 

 insects (Petch, 1911; Burt, 1916) and only with difficulty on the trunks 

 and twigs of trees. The hyphae are hyaline when young, becoming 

 yellowish to dark brown in age. 



The species of Septobasidium may be separated into two groups 

 which would probably be given generic rank, were it not for such transi- 

 tional forms as S. cirratum. In the more primitive group, the fructifica- 

 tion is a loose, arachnoid, flocculent crust, with either unlimited growth 

 at the margin, or restricted growth, resulting in reticulate or sinuously 

 divided fructifications, giving the appearance of foliose lichens. The 



