NYCTALIS ASTEROPHORA 453 



and, when attacked by H. Baryanus, it becomes transformed into 

 .V. jxirasitica. Tulasne remarked upon the similarity in appearance 

 of the chlamydospores of Nyctalis and the chlamydospores of 

 Hypomyces species which are known to be parasitic on agarics 

 and, in a Plate of illustrations, he shows the chlamydospores of 

 Nyctalis along with the perithecia of a Hypomyces.^ However, 

 he expressly pointed out that he had not been able to trace the direct 

 and untrammelled continuation of the two structures in one and 

 the same mycelium. 



In 1859 de Bary 2 investigated Nyctalis asterophora and N. para- 

 sitica anatomically and came to the conclusion that the two forms 

 of chlamydospores developed on the pilei of these species are pro- 

 duced by hyphae which are branches of the pilear hyphae and, 

 therefore, clearly belong to the two agarics in which they are found. 

 The account of Tulasne's investigation on Nyctalis was published a 

 little later than de Bary's. De Bary, finding himself in opposition 

 to so able a mycologist as Tulasne, repeated his observations. 

 However, he again saw that the hyphae which bear the chlamydo- 

 spores are continuous with the hyphae of the Nyctalis pilei, and he 

 was therefore unable to alter his opinion as previously expressed. 

 In 1884 he ^ criticised Tulasne's Hypomyces hypothesis as follows : 

 " If one holds simply to the facts as they present themselves, it is 

 necessary to retain my earlier view, the more so as an Ayaricus 

 parasiticus without one or other of the chlamydospore structures, 

 so far as I know, is entirely unknown. Also, seeing that the structure 

 of the fruit-body of Nyctalis parasitica is so very different from that 

 of N. aster ophora, Tulasne's hypothesis that both these species are 

 forms of the same Agaricus parasiticus, which has suffered a dif- 

 ferent mode of degeneration through the action of the two different 

 parasites Hypomyces parasiticus and H. asterophorus, becomes far 

 more doubtful of belief than my above expressed opinion." 



In 1889 the whole question of the status of the chlamydospores 

 in the two species of Nyctalis was settled once and for all by means 



1 L. R. Tulasne, Selecta Fungorum Carpohgia, T. Ill, 1865, Tab. IX. 

 - A. de Bary, " Zur Kenntniss einiger Agaricinen," Bof. Zeil., Bd. XVII, 1859, 

 pp. 385-388. 393-398. 



•* A. de Bary, Vergleichende Morph. u. Biol, der Pilze, Leipzig, 1884, pp. 361-362. 



