NYCTALIS PARASITICA 461 



(Fig. 191, C, E), and (2) the fact that the fruit-bodies, so far as 

 basidiospores are concerned, are usually quite sterile (Fig. 191, D, 

 E, F). 



The chlamydospores of N. parasitica are smooth elliptical bodies 

 occurring at the ends of, and along the course of, the hyphae in 

 which they are formed (Fig. 191, E, F, G, and Fig. 189, nos. 6-9, 

 p. 456). In a transverse section through a mature gill they can 

 readily be seen in the hyphae of the trama (Fig. 191, D), and Brefeld ^ 

 found them invading even the hymenium (Fig. 189, no. 6, p. 456), 

 thus resembling the chlamydospores of a fertile fruit-body of 

 Ptychogaster citrinus.^ 



De Bary ^ observed that chlamydospore-formation begins in 

 very young pilei which are scarcely 1 line broad and continues 

 almost to the end of the fruit-body's existence (Fig. 191, A, B, C). 

 New chlamydospores are formed : (1) immediately under the ends 

 of the hyphae of the hymenium, which grow in length slowly and con- 

 tinuously and thus add to the thickness of the hymenium (Fig. 191, 

 E, F), and (2) in hyphae which grow into the older gill-layers which 

 already contain chlamydospores, branch there, and so thicken the 

 gills and a.ssist in flattening the pileus. In the end, the substance 

 of each gill consists for the most part of chlamydospores which, 

 since they are present in such large numbers, impart to the gills 

 a dark-brown colour. The hyphae which bear the chlamydospores 

 become very pale and largely disappear, thus setting the chlamydo- 

 spores free. Hence ripe chlamydospores readily fall from the gills 

 in the form of a brown powder.^ This, doubtless, is carried away 

 by the wind. 



So far as basidiospores are concerned, the hymenium of most 

 N. parasitica fruit-bodies is completely abortive, i.e. its elongated, 

 outwardly directed, basidia-like cells produce neither sterigmata 

 nor spores (Fig. 191, D, E, F). 



De Bary ^ examined hundreds of pilei but could never find any 

 basidiospores whatsoever, and my own attempts in this direction 



1 O. Brefeld, he. cit., p. 94. 



2 Cf. Fig. 69, no. 2, p. 154, in F. von Tavel's Vergleichende Morphologie der Pilze, 

 Jena, 1892. This figure, taken from Brefeld's Untersuchungen, will be reproduced 

 in vol. iv. 



3 A. de Bary, loc. cit., p. 395. ■* Ibid. ^ Ibid. 



