336 DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



radiating hyphae, which forms the whole of the upper side of the pileus, produces 

 at an early stage and from all parts numerous stellate spores or macrogonidia of a 

 yellowish brown colour, which I named chlamydospores ; when fully developed it 

 is a yellowish brown layer, which may be I mm. in thickness and ultimately 

 decays (Fig. 162). Lamellae are formed on the under surface of large pilei, and on 

 them basidia which produce four spores, and are usually few in number. The tissue 

 of the under side of the pileus, which bears the lamellae when fully developed, is 

 distinctly different from that of the layer of chlamydospores both in the shape and 

 size of its cells. In young specimens, on the other hand, the Fungus consists entirely 

 of similar hyphae, and there is an uninterrupted connection between the hyphae of 

 the under side of the pileus and those of the chlamydospore-layer, the latter appearing 

 as branches from the former. In some cases no basidia or lamellae are formed. 

 Tulasne states that a third kind of spore is found in the layers of macrogonidia, namely, 

 small colourless cylindrical cells or microgonidia which are abjointed in long rows. 



A second species, Nyetalis parasitica, Fr., which like N. asterophora grows on the 

 larger Agarici, especially Russula adusta, Fr., forms narrowly ellipsoid smooth macro- 

 gonidia in the interior of the whole of the tissue of the thick swollen lamellae, the 

 other parts of the pileus remaining free from them. Tulasne not unfrequently found 

 typical four-spored basidia isolated in the same lamellae as the chlamydogonidia, 

 but I never saw any in my specimens. The view that the gonidia are organs of 

 Nyctalis is founded with regard to both species on the fact, that the hyphae from 

 which they are produced are evidently branches from the rest of the tissue, as seems 

 to have been ascertained beyond doubt in younger specimens. 



Tulasne l has declared against this view. Like Corda, Bonorden, and other writers 

 before him 2 he holds that the chlamydospores (with the microgonidia of N. asterophora) 

 are organs of two Fungi which are parasitic on Agaricus parasiticus, a distinct species 

 which itself lives upon Russula and other forms, and produces more or less degenera- 

 tion in them, and he places these parasites in Hypomyces, a genus of the Sphaeriaceae 

 which lives on other Fungi, under the names of H. asterophorus and H. Baryanus. 

 The grounds of his judgment are the resemblance between these organs and those 

 of the same name in other species of Hypomyces which are known to be parasitic 

 on the Agaricineae, the fact, which I can vouch for, that the chlamydospores sometimes 

 arise isolated on the mycelium of Nyctalis which grows in or on Russula, and lastly 

 the occurrence of indubitable perithecia in company with the gonidia on Nyctalis 

 asterophora. He has not detected any defect in the investigation of the anatomy 

 and life-history of the plant, on which I founded my opinion. 



Tulasne's view is so very probable, that I have taken much pains to find out where 

 my mistake is, but repeated examinations have hitherto always produced the same 

 result. If we simply adhere therefore to the facts before us, we must abide by my 

 first view, especially since Agaricus parasiticus has never been found, as far as I know, 

 without a chlamydospore-apparatus, except perhaps where it is replaced by Nyctalis 

 microphylla of Corda 3 . The structure also of the sporophore of N. parasitica is so 

 very different from that of N. asterophora, that the conjecture that the two forms 

 of Nyctalis are the same Agaricus parasiticus which has been differently altered 

 by different parasites, seems to me much more rash than my own opinion as expressed 

 above. Moreover an experiment of Krombholz by artificial cultivation of the plant 

 seems to afford support to my explanation. Krombholz * sowed the stellate spores of 

 N. asterophora on a young Russula adusta, and as he states with all due precautions, 



1 Ann. d. sc. nat. ser. 4, XIII, p. 5, and Sel. Fung. Carpol. Ill, 54, 59. 



1 See Bot. Ztg. 1859, p. 385. 



3 Icon. IV, Fig. 134. 



' Essbare Schwamme, Heft I, p. 3. 



