VARIOUS OBSERVATIONS 



81 



from all that has just been said that the attempts to graft together 

 species of Coprinus which are not closely related only resulted in 

 failure. 



The confluence of fruit-bodies of one and the same hymeno- 

 mycetous species a phenomenon allied to the artificial grafting 

 together of parts of two fruit-bodies of one and the same species 

 may sometimes be observed in woods and fields. In many 

 Polyporeae, the pilei often become 

 confluent where they happen to 

 come in contact during their peri- 

 pheral extension. Thus, in Poly- 

 stictus perennis, one not infrequently 

 finds two or three fruit-bodies which 

 have a large compound pileus in 

 common but two or three indepen- 

 dent stipes, so that one is reminded 

 of the Indian Banyan tree with 

 its vertical roots supporting the 

 far-spreading branches. Again, 

 Amauroderma salebrosum, an African 

 Polypore, often develops fruit-bodies 

 with fused pilei. Thus in the Her- 

 barium at Kew there is a specimen 

 with two long cylindrical indepen- 

 dent stipes and one round compound 



pileus, the two halves of the pileus evidently representing the 

 two originally separated pilei. In the Agaricineae, on the 

 other hand, confluent pilei only occur as abnormalities and 

 are comparatively rare. Figure 26 shows two confluent pilei 

 of Psathyrella disseminata. The rudiments of the fruit-bodies 

 appear to have originated in the closest proximity, so that 

 possibly the confluence of their pilei and stipe-bases was caused 

 simply by mutual pressure. 1 Where, in the Agaricineae, two 

 pilei become confluent at an early stage of development and 

 one of the fruit-bodies grows more vigorously than the other, the 



1 A similar confluence of two" large Boletus subtommtosus fruit-bodies is to be 

 seen in a photograph kindly sent to me by A. E. Peck. 



FIG. 26. An abnormality in 

 Psathyrella disseminata. The two 

 large fruit-bodies have confluent 

 stipe-bases and confluent pilei. 

 Found near Birmingham, Eng- 

 land. Photographed by J. Ed- 

 monds. Natural size. 



