572 RESEARCHES ON FUNGI 



and the lateral crowding of the basidia are beautiful refinements which, 

 collectively, by increasing the number of spores developed on each unit 

 of area of the hymenium, make an important contribution to the 

 efficiency with which the fruit-body carries on its one dominant function 

 of producing and liberating spores. 



The paraphyses : (1) act as space-making agents separating adjacent 

 basidia ; (2) by gradually increasing in size assist in the expansion of 

 the pileus ; (3) give mechanical support to the individual basidia which 

 they completely surround ; and (4) probably act as nurses to the basidia 

 by supplying them with water and food-substances. 



The removal of the fluid which accumulates at a gill-edge during 

 autodigestion is brought about in part by evaporation and in part by 

 capillary suction into the trama. 



Illustrations are given showing the manner in which Coprinus comatus 

 is parasitised by Stropharia epimyces. Attempts to parasitise Coprinus 

 sterqiiilinus with the Stropharia failed. The origin of the parasitic habit 

 of Stropharia epimyces is discussed. 



Some fruit-bodies of Coprinus comatus of normal size and appearance 

 were obtained in pure cultures in the laboratory. The mycelium was 

 grown on a mixture of horse dung and sawdust covered with a thick layer 

 of soil. 



Chapter VIII. — Coprinus sterquilinus has been described as C. ob- 

 lectus by Bolton, as C. stenocoleus by Fries, and as C. macrosporus by 

 Peck, its structure is similar to that of C. comatus and it belongs to 

 the Comatus Sub-type of organisation. When its spores are sown on 

 sterilised horse dung in the laboratory, it passes through its life-history 

 from spore to spore in about 30 days. 



The author describes the maturing fruit-body, the structure and 

 development of the hymenium, the discharge of the spores, and the 

 phenomenon of autodigestion in detail. 



The most rapid rate at which the stipe elongates is about 1 cm. an 

 hour. The greatest amount of growth in length in an elongating stipe 

 takes place at the apex just underneath the pileus. The blackening of 

 the upper part of the stipe is a normal process due to a development of 

 dark pigment in the cell-sap of the hyphae, and it cannot be caused, as 

 stated in systematic works, by bruising. 



The basidia are dimorphic. The arrangement of the spores at two 

 different levels above the general surface of the hymenium is illustrated 

 by photomicrographs. Nuclei can be seen in the living basidium-body 

 and in young and living spores. The long basidia begin to develop 

 sterigmata and spores before the short basidia so that the long and the 

 short basidia must be considered as a first and a second generation of 

 basidia respectively. 



When a basidium is developing, its body becomes laden with gly- 

 cogen. The young spores also come to contain glj-cogen. Later, the 



