230 RESEARCHES ON FUNGI 



them and emerge in the soHd faeces where they germinate and 

 produce a mycelium which, in the course of a few weeks, gives rise 

 to new fruit-bodies and new crops of spores. This being so, it is 

 of the greatest importance that the spores which have settled on 

 the grass in pastures shall adhere very firmly to the grass and not be 

 dislodged in the course of many weeks or even months by either 

 violent winds or heavy rains. The adhesion of the spores, as a 

 matter of fact, is secured (1) by the spores falling through the air 

 with their more rounded side downwards, and (2) by their more 

 rounded side, which comes into contact with the substratum, being 

 provided with a very adhesive, colourless wall-meniscus which is 

 insoluble in water. It thus appears that the presence of the colour- 

 less wall-meniscus on the exterior of a C. sterquilinus spore, the 

 exact position of the meniscus, and the adhesive property with 

 which the meniscus is endowed are all correlated with the part 

 played in the life-history of the fungus by horses and other 

 herbivorous animals. 



The Discharge of the Spores and the Phenomenon of Auto- 

 digestion. — We have already seen that a wave of hymenial develop- 

 ment passes from below upwards on each gill and that, as a conse- 

 quence, the spores ripen in succession from below upwards. Whilst, 

 owing to this ripening process, the gills are becoming black from 

 below upwards, the pileus begins to expand (Fig. 97, B and C ; 

 also Fig. 75, p. 186) ; and, after the gills have become completely 

 blackened from bottom to top, the pileus becomes campanulate 

 (Fig. 97, D ; also Fig. 76, p. 187). 



When the pileus has become expanded to about the extent shown 

 in Fig. 97, D, the process of spore-discharge begins. The photo- 

 graph reproduced in Fig. 77 (p. 188) shows a fruit-body in which 

 the discharge of spores had just begun. The first spores to be 

 discharged are those which are situated in a narrow zone which 

 extends along both sides of the extreme lower margin of each gill 

 {s in Fig. 97, E). The zone of spore-discharge, after thus coming 

 into existence, gradually moves upwards on each gill from the 

 bottom to the top ; and, in large fruit-bodies growing in the 

 laboratory, it was observed to complete its ascent in from eight 

 to twelve hours. 



