270 RESEARCHES ON FUNGI 



destined from the first to remain sterile, are present in the hymenium 

 or not. When it has been asserted that paraphyses are present, 

 no sufficient means has been pointed out to distinguish them from 

 the young basidia. So far, also, no account has ever been given 

 of the changes which take place in the exhausted basidia ; and 

 certain investigators even hold that, in some species, a basidium 

 may produce more than one generation of spores. 1 Finally, no 

 mycologist in recent decades has attempted to make a correct 

 drawing of the hymenium as seen in surface view, so that, hitherto, 

 the relations of the hymenial elements to one another in space 

 have been nowhere sufficiently illustrated. 2 



One of the best illustrations of the hymenium of an Agaric 

 hitherto published is that of Russula rubra in Strasburger's well- 

 known Text-book of Botany. 3 In this, in cross-section only, are 

 shown one cystidium, four spore-bearing basidia, and some eight 

 other club-shaped elements. The largest of these sterile elements 

 is labelled with a p which, according to the text, stands for 

 paraphysis. There is nothing said to help the reader to interpret 

 the nature of these cells. Are these eight elements destined to 

 remain sterile, or are they of mixed nature, some being young 

 basidia, i.e. about to produce spores, and others permanently 

 sterile paraphyses ? The student is left to guess the answers to 

 these questions. Then again, the illustration is unsatisfactory in 

 that it does not contain any exhausted basidia, i.e. basidia which 

 have shed their spores. It is unlikely that any student would 

 take a gill for sectioning at the precise moment when it was about 

 to shed its very first spores. Usually, in laboratory practice, a 

 pileus is taken when it has been shedding spores for some time. 

 In a typical hymenial illustration, therefore, some exhausted 

 basidia ought to be included. From this discussion, I think it 



1 Vide Chap. I, p. 27. 



2 For surface-view illustrations of Non-Coprinus Agaricineae we have to go 

 back to the pioneers in the investigation of the hymenium of the Hymenomycetes, 

 e.g. LeveiUe (1837), Berkeley (1838), Corda (1839), etc. Brefeld, in 1877, gave 

 a plan of the relative positions of the basidia and paraphyses for a species of 

 Coprinus (Untersuchungen, Heft III, Taf. IV, Figs. 10 and 14). 



3 Strasburger, Schenck, Noll, and Karsten, A Text-book of Botany, Third English 

 (based on eighth German) edition, London, 1908, p. 408. 



