30 RESEARCHES ON FUNGI 



constantly in the vast majority of species, from Corticium to 

 Coprinus, from Clavaria to Cortinarius, from Stereum to Schizo- 

 phyllum, from Hydnum to Hygrophorus, and from Polyporus 

 to Panaeolus. In the Tremellineae, which seem to form a link 

 with the Uredineae, although the symmetry of the basidium is 

 less striking than in the Thelephoreae, the Clavarieae, the Hydneae. 

 the Polyporeae, and the Agaricaceae, the sterigmata and spore-hila 

 are always well developed. In the non-tremelloid groups, a 



FIG. 10. Scleroderma vulgare, a gastromycetous fungus, lacking sterigmata, 

 commonly found under Oak trees, etc. Photographed by A. E. Peck at 

 Scarborough, England. Natural size. 



few species have bisporous basidia and some others hexasporous ; 

 but, in these and all other exceptional species, the sterigma and 

 hilum have the normal development, and the different sterig- 

 mata and spores are symmetrically arranged at the end of the 

 basidium-body . 



In the Gastromycetes, on the other hand, the basidium has no 

 typical or almost constant form. The number of spores on an 

 individual basidium varies much. Thus in Scleroderma vulgare 

 the number is from 2 to 5, while in Phallus impudicus it is 

 usually about 9, these being packed tightly together, side by side 

 in a bundle at the end of the basidium. The spore-hilum is usually 

 not (perhaps never) developed at all. One may look for it in vain, 



