454 RESEARCHES ON FUNGI 



of a brilliant piece of cultural work carried out by Brefeld.^ Brefeld 

 not only repeated the experiment of Krombholz, i.e. sowed chlamydo- 

 spores of Nyctalis asterophora on the pileus of a Russula and obtained 

 fruit-bodies of N. asterophora as a result, but he traced the life- 

 history of N. asterophora by means of pure cultures.^ His observa- 

 tions 3 on N. asterophora were as follows : 



So far as basidiospores are concerned, most of the fruit-bodies 



of Nyctalis asterophora are completely sterile, for fertile basidia 



are only found exceptionally on fruit-bodies which are large and 



vigorous. If freshly deposited basidiospores are sown in a decoction 



of Russula fruit-bodies, they germinate readily and produce small 



myceha. In each mycelium some of the branches soon begin to 



break up into chains of oidia (Fig. 189, nos. 2 and 3) resembUng those 



of Endomyces decipiens among the Ascomycetes and of many 



Hydneae and Polyporeae among the Autobasidiomycetes. The 



oidia in their turn germinate readily and produce mycelia which 



again break up into oidia. In a series of generations produced by 



oidia oidia-formation becomes less and less pronounced and more 



and more replaced by the vegetative growth of the hyphae. At 



the same time typical stellate chlamydospores, just like those 



occurring in the upper stratum of a pileus, begin to be formed in the 



hyphae, at first along with oidia, but subsequently alone (Fig. 189, 



nos. 1 and 4). The hyphae which give rise to chlamydospores are 



all made up of cells which are separated from one another by walls 



bearing clamp-connections. The chlamydospores are constructed 



at the end of the hypha or along its course, and chains of chlamydo- 



1 0. Brefeld, "Die Gattung Nyctalis," Untersuchnngen iiber Pike, Leipzig, 

 Heft VIII, p. 70 et seq. 



2 Any one who desires to gain an insight into Brefeld's methods of research 

 and the extraordinary skill wth which he was able to bring to a successful con- 

 clusion a difficult piece of experimental work, could not do better than read care- 

 fully the account of his researches on the life-history of Ntjclalis asterophora and 

 N. parasitica. His solution of the chlamydospore question was a veritable triumph, 

 and one can readily understand the satisfaction and pleasure with which he must 

 have written down his results and presented them to the botanical world. If 

 Brefeld had done no more than provide us with his account of Nyctalis, he would 

 have done enough to compel us to regard him as one of the ablest botanists of the 

 nineteenth century. 



3 These observations are well summarised by F. von Tavel in his Vergkichende 

 Morphologie der Pilze, Jena, 1892, pp. 168-170. 



