THE VIOLENT PROJECTION OF SPORES 137 



cineae, 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 was usually found unnecessary in a quiet 

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

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

 the species which were examined. As in the case of Polyporus 

 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 with gills. The hymenial surfaces are 



c vertical. About 4 times natural size. 



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 O'l mm. before the horizontal motion was destroyed. 

 The Agaricinea3 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, Panreolus, Psilocybe, 

 Colly bi a, Cantharellus, Laccaria, Hygrophorus, Nolanea, Hypholoma, 

 Marasmius, Entoloma, Mycena, and Armillaria. 



The first method of observing spore-fall with the microscope 

 in the Polyporeae and Agaricinese appeared to yield two facts in 

 favour of the supposition that the spores are violently discharged 

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

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



