132 RESEARCHES ON FUNGI 



the protoplasm in the cells is due to a peptonising enzyme which 

 can be extracted from the gills but not from the stipe. There is 

 more of this enzyme in the upper part of a gill than in the lower. 

 The lamellae contain, in addition, catalases, peroxidases, and traces 

 of oxidases, but no diastase. Lipoid enzymes were not definitely 

 detected. Enzymes capable of destroying the chitin, etc., making 

 up the cell-walls, were not extracted. Bacteria were found among 

 the membranes undergoing destruction, and Cappelletti suggested 

 that the membranolytic action is due to them.^ 



It is true that bacteria may be found contaminating the fluid- 

 products of autodigestion at the gill-edge, but Cappelletti's sup- 

 position that normally they are responsible for the breaking-down 

 of the cell-membranes seems to me not only very unlikely on a 

 -priori grounds but to be disproved by observations made upon pure 

 cultures. In my laboratory very many pure cultures of Coprinus 

 sferquilinus, C. lagopus, C. yiiveus, C. narcoticus, C. stercorarius, etc., 

 have been made from spores, in which bacteria have been completely 

 excluded. Yet, notwithstanding the absence of bacteria in these 

 cultures, autodigestion of the gills has proceeded in a perfectly 

 normal manner. Enzymes responsible for destroying the cell- 

 membranes during autodigestion are therefore always produced by 

 the gills themselves. 



Critical Remarks on the Generic Position of Certain Agaricineae. 

 — Hitherto there has been a good deal of confusion in regard to the 

 relation of certain Agaricineae to the genus Coprinus. This applies 

 in particular to the genus Bolbitius and to the following species : 

 Psathyrella disseminata, Psathyra urticaecola, and Coprinus pli- 

 catilis. The secret of coming to a correct conclusion as to the 

 generic positions of these fungi lies in applying to them as a test 

 the seven criteria which were laid down at the beginning of this 

 Chapter in connection with the definition of the Coprinus Type of 

 fruit-body. Already, in Chapters II and III, by proceeding in this 

 way, I have demonstrated that Psathyrella disseminata and Bol- 

 bitius flavidus each have an organisation for the production and 

 liberation of spores which is entirely different from that of Coprinus ; 

 and I have felt justified in asserting, firstly, that the genus Bol- 



1 0. Cappelletti, loc. cH., pp. 88-89. 



