154 



INTRODUCTION TO THE STUDY OF FUNGI 



attached spores. These lentil-shaped bodies are analogous to 

 the peridiola in such genera as Polysaccum and Arachnion, 



but all the inter- 

 vening plasma has 

 been dissolved away, 

 so that they remain 

 free within the peri- 

 dium. In all the 

 species the sporan- 

 gioles are very hard 

 and firm when 

 mature, and the con- 

 tents are never 

 powdery. In some 

 species the external 

 peridium has asqua- 

 mose or hairy surface 

 but in a few species 

 it is nearly smooth. 

 Sometimes the upper 

 third of its length 

 is marked with con- 

 spicuous parallel 

 channels or striae. 

 In Cyathus the peri- 

 dium is composed of three superimposed layers, and in 

 Crucihulum of two. 



Having disposed, in a summary manner, of these two 

 families, we return to the Trichogasters which form the bulk 

 of the order, and especially the Zycoperdaceae. Probably the 

 genera which contain the largest , number of known species 

 are Lycoperdon, Geaster, and Bovista. In these the peridium 

 is more or less distinctly double, but there are allied genera 

 in which the peridium is simple. The delicate threads, found 

 mixed with the spores when mature, forming the capillitium, 

 are an important element in classification. In the mature 

 gleba they seem to be entangled, and indefinite as to their 

 origin in Lycoperdon and Bovista, but in other genera they dis- 

 tinctly radiate from the columella to the inner wall of the 



Fig. 64. — Crucihulum vulgare. After Greville. 



