GENERAL SUMMARY 267 



afterwards, the majority of spores of the Mushroom, &c., become electrically 

 charged. The charges are relatively of different strengths, and either 

 positive or negative. A few spores appear to be unelectrified. No bio- 

 logical significance has been ascribed to these facts. 



Chapter XIX. — In the Agaricinere there are two distinct spore-produc- 

 ing and spore-liberating types of fruit-body — the Coprinus romatus type and 

 the Mushroom type. These differ from one another in several structural 

 and developmental details. 



In the Coprini " deliquescence " is a process of autodigestion which 

 renders important mechanical assistance in the process of spore-discharge. 

 It was more especially studied in the case of Coprinus comatus. The spores 

 on each gill ripen and are discharged in succession from below upwards. 

 Autodigestion leads to the removal of those parts of the gills which have 

 already shed their spores and thus permits of the continued opening out of 

 the pileus. By this means the necessary spaces for the violent discharge 

 of the spores from the basidia are provided. The spores, after describing 

 sporabolas, fall vertically downwards between the gills. On emerging from 

 the pileus they are scattered by the winds. " Deliquescence " is in no way 

 connected with the visits of insects to the fruit-bodies. 



The genus Coprinus may be regarded as a specialised offshoot from 

 a more generalised fungus of the Mushroom type. There appears to be 

 no satisfactory evidence in support of Massee's view that " in the genus 

 Coprinus we have in reality the remnant of a primitive group from which 

 have descended the entire group of Agaricinese." 



Chapter XX. — One of the chief functions of the stipe is to provide 

 a space usually one or more inches high between the under surface of the 

 pileus and the substratum on which the fruit-body may grow. Owing to 

 the very small rate of fall of the spores and the relatively very much 

 greater average horizontal speed of air-currents near the ground, the 

 space is amply sufficient under normal conditions to permit of the falling 

 spores being carried away from the fruit-body and deposited at a distance 

 from it. 



Falck's theory, that the heat produced in pilei by respiration and in 

 consequence of the presence of maggots is of importance in creating con- 

 vection currents which scatter the spores, has been discussed. If partially 

 true, it is of limited application, and further investigations are necessary 

 in order to decide its value. 



Chapter XXI. — Coprophilous Hymenomycetes have fruit-bodies 

 adapted to their peculiar habitat both in form and in reactions to external 

 stimuli. 



