280 RESEARCHES ON FUNGI 



or absence of paraphyses, I made use of the discovery already 

 recorded that exhausted basidia can always be distinguished from 

 other elements by their concave ends and by the sterigmatic particles 

 which remain on their tops after collapse has taken place. It was 

 argued that, if one were to study the surface of a hymenium in face 

 view, from the beginning to the end of spore-discharge, then not 

 only would the basidia become more and more easily recognisable 

 owing to more and more of them becoming exhausted, but the 

 paraphyses with their plain rounded tops should become, by con- 

 trast with the basidia, more and more conspicuous. It also seemed 

 probable that the hymenium, after the spores had all been discharged, 

 would present to the eye only two kinds of elements : ( 1 ) exhausted 

 basidia to be distinguished by their sterigmatic particles, and 

 (2) sterile paraphyses to be distinguished by their smooth rounded 

 tops and impoverished protoplasmic contents. With a view to 

 testing these suppositions, a fruit-body of Panaeolus campanulatus 

 was grown on horse dung in the laboratory ; and from its pileus, 

 day by day, from the beginning of spore-discharge to the end, there 

 was dissected of! a succession of gills for microscopic study. The 

 hymenium on each gill was examined in face view. The results 

 of the investigation, which was continued for upwards of a week, 

 fully justified the suppositions which had been made. 



A small piece (one two-hundredth part of a square mm.) of a 

 completely exhausted hymenial layer is shown in Fig. 95 at A, 

 In it there are two kinds of elements only exhausted basidia and 

 paraphyses. A waste spore, i.e. one which did not succeed in leaving 

 the hymenium, is shown on the right. The paraphyses of Fig. 95, A, 

 are set out by themselves in Fig. 95, B. A count (including 

 elements sketched in part only) results in the finding that on the 

 whole area the basidia are about equal in number to the paraphyses. 

 Actually, the basidia are to the paraphyses in the proportion of 

 47 to 50. The tops of the basidia, which are by far their widest 

 parts, pass down into an attenuated shaft, and they rest on the 

 tops of the adjacent paraphyses. The latter are almost spherical 

 elements and, since they are turgid, are doubtless still living. At 

 the end of the spore-discharge period, therefore, the basidia are all dead 

 and the paraphyses are all living. The paraphyses, as comparative 



