THE VIOLENT PROJECTIOX OF SPORES 



137 



cinese, tangential sections about 1-2 mm. thick were made through 

 the pilei, so as to cut the gills transversely. The sections were then 

 placed on a microscope slide, by which means the hymenial surfaces 

 took up a vertical position (Fig. 48). Sometimes the sections were 

 placed in a glass cell closed with a cover-glass, but this precaution for 

 keeping off air-currents w^as usually found unnecessary in a quiet 

 room where the air was still. The spores appeared to be violently 

 projected from the hymenium into the spaces between the gills in all 

 the species which w^ere examined. As in the case of Polyporiis 

 squamosus, however, only part of the path of each spore could be 

 observed, owing to the fact that only one plane can be focussed at 

 one time by the microscope. The discharge of the spores could 

 usually be detected almost immediately the section had been made, 

 and continued for some minutes 

 until loss of water from the gills 

 interfered with the process. In 

 small, closed glass chambers, 

 where loss of water vapour was 

 prevented, the discharge of 

 spores continued in some in- 

 stances for several hours. The 

 spore zone of discharged spores 

 on the glass slide between two 

 gills and adjacent to the base of each was in most cases about 

 0*2 mm. wide. The impression was gained that the spores had been 

 projected about 0"1 mm. before the horizontal motion was destroyed. 

 The Agaricinese used as material for these observations consisted of 

 thirty-one species common in the Midlands of England, and included 

 in the following genera: Psalliota, Stropharia, Anellaria, Galera, 

 Amanitopsis, Amanita, Lactarius, Russula, Pameolus, Psilocybe, 

 Collybia, Cantharellus, Laccaria, Hygrophorus, Nolanea, Hypholoma, 

 Marasmius, Entoloma, Mycena, and Armillaria. 



The first method of observing spore-fall with the microscope 

 in the Polyporese and Agaricinete appeared to yield two facts in 

 favour of the supposition that the spores are violently discharged 

 from the sterigmata: (1) The spores could apparently be seen 

 travelling horizontally away from the basidia, and (2) the spores 



Fig. 48. — Diagram to show the shape of 

 a section from the pileus of an Agaric 

 with gills. The hymenial surfaces are 

 vertical. About 4 times natural size. 



