200 RESEARCHES ON FUNGI 



long and the short basidia on a small area. The spores were all 

 equally black in appearance ; but, for the sake of clearness, the 

 spores of the long basidia have been uniformly blackened whilst 

 those of the short basidia, which lie at a lower level, have been 

 cross-hatched. In B is given a plan of the arrangement of the 

 basidia and paraphyses after the removal of the spores. The long 

 basidia have been shaded and the short ones left unshaded. It 

 is impossible, owing to optical difficulties, to make a camera-lucida 

 drawing which includes the spores as well as the outlines of the 

 basidia and paraphyses. A semi-diagrammatic drawing of this 

 kind, however, is shown at C. It was constructed by adding to 

 the camera-lucida drawing A the requisite basidia and paraphyses 

 in a diagrammatic manner, using as a basis the camera-lucida 

 drawing B. 



As further illustrations of the hymenium when seen in face 

 view we may consider the photomicrographs shown in Figs. 85 

 and 86, The apparatus with which they were made has already 

 been described in Volume II in connection with an account 

 of a photomicrograph of the hymenium of Anellaria separata} 

 However, instead of an arc-lamp, which was not available when 

 required, an electric-light bulb was employed, with the result that 

 the exposure had to be lengthened from about four seconds to four 

 minutes. In making the prei^aration to be photographed, a piece 

 of a gill bearing fully pigmented spores was dissected from a fruit- 

 body grown in the laboratory and laid flat on a glass slide. A 

 cover-glass was then lightly placed above it to prevent rapid drying. 

 The preparation was therefore mounted in air and not in water. 

 The photomicrograph reproduced in Fig. 85 was taken with the 

 low power of the microscope and has a magnification of 140 

 diameters. The spores in focus are those of the short basidia, the 

 spores out of focus being those of the long basidia. The tops of 

 the shafts of the long basidia can be seen in places, notably along 

 the upper edge of the photograph toward the right. A study of 

 this photograph will assist the reader in realising that everywhere 

 in the hymenium the long and the short basidia are about equally 

 interspersed, and that there are no cystidia on the sides of the 



1 Vol. ii, 1922, pp. 357-359. 



