426 RESEARCHES ON FUNGI 



element no. 59 to element no. 63, and another intermediate area 

 from element no. 1 to element no. 8. As indicated by the shading, 

 the spores in the light area are unpigmented, in the intermediate 

 areas partially pigmented, and in the dark area fully pigmented. 



The hymenial elements can all be classified as basidia or para- 

 physes as follows : past-generations basidia, nos. 13, 21, 30, 38, 

 and 51 ; present-generation basidia, nos. 3, 5, 11, 16, 24, 32, 41, 

 44, 48, 53, 57, and 61 ; coming-generation basidia, nos. 8, 18, 

 28, 36, 42, 46, 55, and 60 ; future-generations basidia, nos. 2, 6, 7, 

 9, 12, 14, 17, 19, 23, 27, 29, 31, 34, 37, 45, 49, 52, 54, 59, and 62 ; 

 paraphyses (permanently sterile elements), nos. 1, 4, 10, 15, 20, 

 22, 25, 26, 33, 35, 39, 40, 43, 47, 50, 56, 58, and 63. 



The past-generations basidia have shed their spores and are all 

 dead. They were once as protuberant as the present-generation 

 basidia but their ends are now drawn down to the general level of 

 the hymenium. The free end of each past-generation basidium 

 appears flattened in side view, but is in reality concave, the 

 concavity concealing the sterigmatic stumps. The collapsed shafts 

 are often somewhat brownish, a discoloration which aids one in the 

 not too easy task of identifying them. 



A basidium which fails for any reason to discharge its spores at 

 the proper time, on collapsing, draws down its spores to the general 

 level of the hymenium, so that they cannot interfere mechanically 

 with the new spores developing on the sterigmata of neighbouring 

 basidia. Two such undischarged or wasted spores which are now 

 lying on, and adhering to, the hymenium, are shown in Fig. 147 at 

 w w. Each of them was dragged down to its place of rest during 

 the collapse of a past-generation basidium. The waste spore, w, 

 on the right of the illustration, is supposed to have been produced 

 by the element no. 51, but the basidium which produced the other 

 waste spore is not shown. 



The present-generation basidia all bear sterigmata and spores. 

 Their bodies protrude above the general level of the hymenium to 

 a distance of about 0-005 mm. The spores. are raised up on sterig- 

 mata, where, during their development and discharge, they cannot 

 be interfered with mechanically either by the wasted spores or by 

 the tops of neighbouring younger basidia. The age of the spores 



