280 THE BASIDIOMYCETES 



to possess 2 nuclei in Cantharellus corimcopioides, Coprimis 

 ephemerus, HydnaiJghini carneimt, Myceiia nmrina, and FsaUiota 

 campestris. In some species that produce only 2 uninucleate ba- 

 sidiospores, the 2 residual nuclei disintegrate in the basidium. 

 In species that have 4 spores, such as Mycena atkinsoni, M. alca- 

 Una, M. heviisphaerica, M. leptocephalay M. sanguineolenta, M. 

 stannea, and M. viscosa, there may be 4 residual nuclei to dis- 

 integrate [Smith (1934)]. Alycena citrinoinargijiata, M. dis- 

 siliens, M. leptocephala, M. polygi'amma var. albida [Smith 

 (1934)] and Naiicoria lenticeps may produce 2, 3, or 4 spores on 

 different basidia in a single pileus. Galera silignea is said to have 

 monosporous basidia. Smith (1934) also noted that the young 

 basidia of Mycena capillaris, M. cholea, AI. citrinomarginata, M. 

 dissUienSy M. lasiosperrna, M. leptocephala, M. poly gravmia var. 

 albida, M. roseo-pallens, M. riibromarginata var. laricis, and M. 

 vitilis have a single nucleus, instead of 2, in the young basidium. 

 These species are considered parthenogenetic. 



Spindle orientation in basidia of Hymenomycetes and Gastro- 

 mycetes may be transitional between stichobasidial and chiasto- 

 basidial, as noted by Levine (1913) in Boletus, or each kind may 

 occur in adjacent basidia in the same hymenium, as in Exoba- 

 sidhim rhododendri [Eftimiu and Kharbush (1927)]. 



Basidiospores. The basidiospores of Basidiomycetes generally, 

 except among the Gastromycetes, are inaequilateral, unicellular, 

 uninucleate, thin-walled structures. They may vary in color en 

 masse, being hyaline, pink, yellow, brown, or black, but other- 

 wise are monotonously alike. Their wall is almost universally 

 smooth, echinulations being common in a few genera, such as 

 Lactarius and Russula. In Ganoderma the walls are peculiarly 

 thickened. In Auricularia, Dacryomyces, and related genera the 

 basidiospores may become several times transversely septate. The 

 basidiospores of many Gastromycetes have thick walls that are 

 variously ornamented,, and the spore mass may be yellow, brown, 

 purple, or black. 



Mycelium. The conspicuous part of most species of Basidio- 

 mycetes is the fructification. The mycelium is usually en- 

 sconced within the leaf mold, decaying wood, dung, or other 

 organic matter of the soil or within plant tissues. Here it exists 

 as an interlacing, anastomosing weft of hyphae, as delicate my- 

 celial strands, or as conspicuous rhizomorphs or sclerotia. The 



