50 



RESEARCHES ON FUNGI 



and about to be discharged, are shown in uniform black. The spores 

 of the fourth and last generation of basidia, d, which have already 

 begun to be affected by the process of pigmentation, are lightly shaded. 

 One is struck, when examining the hymenium as a whole, by the uni- 

 form nature of the development. From such an illustration as has 

 just been described one can readily understand why it is that, to the 

 naked eye, the sides of the gills never show the least trace of mottling 



^^@® © ©• ® ® • • 





ab.<^1L% ••' 



Fig. 28. — Psathyrella disseminata. Surface views of the hymenium from drawings 

 made with the camera lucicln. A shows : 06, the collapsed basidia of the first 

 and second basidial generations ; c, the ripe or almost ripe spores of the third 

 basidial generation ; and d, the ripening spores of the fourth basidial generation. 

 B, a plan showing the relative positions of the basidia, b, and the paraphyses, 

 p. Magnification, 586. 



but appear to be uniformly grey (c/. Fig. 26, A, p. 44). In Fig. 28 

 at B are shown the well-developed paraphyses which are united into 

 a system. They never produce spores and evidently function as 

 sterile space-makers in that they keep adjacent basidia sufficiently 

 far from one another to secure the proper freedom of the spores 

 during their development and discharge. 



The semi-diagrammatic cross-section represented in Fig. 29 will 

 throw further light on the structure of the hymenium. The first 

 generation of basidia, a a a, is the most protuberant, the second 

 generation, b b, less protuberant, the third, c c, still less protuberant, 

 and the fourth, d d d, so far as their bodies are concerned, not pro- 



