62 RESEARCHES ON FUNGI 



(6) The basidia are monomorphic, i.e. equally protuberant. In 

 this respect the Bolbitius Sub- type agrees with the Panaeolus, 

 the Inocybe, and the Armillaria Sub-types, but differs from the 

 Psathyrella Sub-type, and from all the Coprinus Sub-types which 

 make up the Inaequi-hymeniiferae. The amount of protuberancy 

 of the basidia beyond the general level of the paraphyses is con- 

 siderable, but not nearly so great as that of the longest set of basidia 

 in Psathyrella disseminata, Lepiota cepaestipes, and the Coprini. 



(7) There is no lateral crowding of the basidia with overlap of 

 spores such as is found in the Psathyrella Sub-type and in the 

 Coprinus Sub-types, but adjacent spore-bearing basidia are separated 

 by spaces equivalent to those found in the Panaeolus Sub-type. 



(8) The paraphyses are relatively large and well-developed. 

 They are joined together laterally so as to form a thin flat sheet 

 of tissue through which the isolated basidia protrude. A similar 

 system of paraphyses occurs in the ephemeral Psathyrella and 

 Coprinus Sub-types, but is absent from the Panaeolus, the Inocybe, 

 and the Armillaria Sub-types which have more persistent fruit- 

 bodies. In the latter Sub-types, the paraphyses are relatively 

 smaller and not linked into a continuous system. The paraphyses 

 act as space-making agents in that they separate the basidia during 

 the production and liberation of the spores ; and, by their rapid 

 growth, they also serve to enlarge the superficial area of the gills 

 during the rapid expansion of the pileus. 



(9) In the two species of Bolbitius which I have examined, the 

 basidia have a peculiar shape which may well be characteristic for 

 the whole genus. The inner half of each basidium consists of a 

 narrow cylindrical or slightly tapering shaft entirely enclosed by 

 paraphyses. This shaft, on passing out between the paraphyses 

 to the exterior of the hymenium, suddenly bulges into a more or less 

 globular swelling which constitutes the outer half of the basidium. 

 This swelling is the protuberant part of the basidium and upon it 

 arise the sterigmata. 



From the above, it will be noticed that the chief difference 

 between the Bolbitius and the Psathyrella Sub-types lies in the fact 

 that, whereas in the former the basidia are monomorphic, not 

 crowded laterally, and not as a rule arranged in a definite series of 



