GENERAL SUMMARY 575 



Aequi-hymeniiferae, e.g. Pluteus cervinus, are correlated in each group 

 with the mechanism employed for securing the successful production 

 and liberation of the spores. 



In conclusion a brief description, accompanied by illustrations, is given 

 of Coprinus narcoticus, C. stercorarius, C. macrorhizus, and C. picaceus, 

 all of which resemble C. atramentarius in possessing cystidia which inter- 

 lock and separate the gills during the spore-discharge period. 



Chapter X. — In the Lagopus Sub-type : (1) the gills are parallel- 

 sided and without conspicuous flanges ; (2) cystidia are present in 

 considerable numbers on the gill-sides ; (3) the existence of the inter- 

 lamellar spaces on the young and unexpanded pileus is secured by 

 the presence of the cystidia which bridge the interlamellar spaces ; 

 (4) before spore-discharge begins, the pileus expands umbrella- wise and 

 adjacent gills become widely separated from one another, so that the 

 cystidia no longer bridge the interlamellar spaces but merely project 

 from the gill-sides like pegs ; (5) the basidia are usually dimorphic — 

 long and short ; (6) the pileus-flesh and gills become cleft from above 

 downwards so as to form conspicuous radial sulcations on the top of the 

 pileus ; and (7) the ratio of the length of the gills to the breadth is higher 

 than in the Atramentarius Sub-type. Included in the Lagopus Sub- 

 type are : Coprinus lagopus, C. domesticus and C. niveus. 



Coprinus lagopus is regarded as identical with C. cinereus but as dis- 

 tinct from C. macrorhizus. The name C. fimetarius has been applied by 

 various authors both to C. lagopus and C. macrorhizus, and has therefore 

 been discarded. 



The author gives a full description of Coprinus lagopus and pro- 

 vides illustrations of : (1) wild fruit-bodies including dwarfs, (2) fruit- 

 bodies obtained in pure cultures, (3) fruit-bodies grown in the dark, and 

 (4) sterile fruit-bodies. 



Coprinus lagopus is heterothallic. Fruit-bodies developed on a 

 myceUum of monosporous origin are always sterile in a greater or less 

 degree in that they produce either no spores at all or relatively few spores. 

 When spores are produced on one of these partially sterile fruit-bodies, 

 they are all of one and the same sex — the same sex as the spore which 

 gave rise to the mycelium upon which the fruit-body was developed. 

 Sterile fruit-bodies are occasionally developed on a secondary mycelium 

 that has originated by the union of two mycelia of opposite sex. All 

 the normal fully fertile fruit-bodies of C. lagopus, which we see coming 

 up on unsterilised horse dung in the open air or in the laboratory, are 

 produced on secondary mycelia, i.e. on mycelia which have resulted from 

 the fusion of two primary mycelia of opposite sex. 



The production and liberation of spores is accomplished in Coprinus 

 lagopus in the same manner as in C. atramentarius except for the fact 

 that in C. lagopus, before spore-discharge begins, the pileus expands 

 and the interlamellar spaces become greatly widened so that the cystidia, 



