AGARICALES 459 



palisade layer splits over these ridges as it often does in Cladoderris, 

 and the edges grow downward, followed by a growth of the hymenial 

 plates. This growth continues throughout the life of the fructification. 

 Earlier authors, as Fries, Fayod (1889) and Buller (1909), had sup- 

 posed that the lamellae were first formed and later split due to hygro- 

 scopic tension. While Schizophyllum commune is a weak wound parasite, 

 it is probable that most of the damage attributed to it is caused by other 

 Basidiomycetes which grow more slowly and hence do not reveal their 

 presence by production of fructifications as soon as this species. 



Tricholomateae. — This tribe is connected to the higher Clitocybeae 

 from which it is often difficult to separate. Some species whose lamellae 

 are separable from the pileus {e.g., Cortinarius largus) remind one of the 

 Paxilleae. Tricholoma nudum (Rhodopaxillus nudus) and T. Georgii 

 are gymnocarpous (Kuehner, 1926). The partial veil is retained in 

 some genera, in Armillaria as a ring and in Cortinarius as a cortina. 

 As far as the ontogeny of the fructifications has been investigated, as in 

 Inocybe (Douglas, 1920), Cortinarius (Douglas, 1916; Sawyer, 1917; 

 Kuehner, 1926) and Armillaria (Fischer, 1909; Beer, 1911; Atkinson, 

 1914, 1915), a blemmatogenous layer is differentiated at the periphery 

 of the fundament of the fructification. This layer generally remains 

 connected with the underlying layer of tissue, particularly in the pileus 

 and partial veil; the remnants may be observed as scales on the upper 

 surface of the pileus after the expansion of the fructification. 



Armillaria mellea (Clitocybe monadelpha, Armillariell melleaa) has an 

 enormous economic significance as a destroyer of forests. Its brown to 

 black rhizomorphs, often anastomosing to layers of tissue in tree trunks, 

 at times phosphorescent, spread through the ground for considerable 

 distances. They send slender hyphae which penetrate the collar and the 

 roots of frondose species, destroy the cell walls at the butt and cause a 

 white rot of the wood and the death of the tree. 



Amaniteae. — In this tribe, the Agaricaceae reach their highest point. 

 Differentiation has proceeded further than in the previous subfamilies: 

 pileus and stipe differ from each other in structure and usually may be 

 easily separated from each other. In all genera recently investigated, 

 as in Hypholoma (Allen, 1906; Beer, 1911), Tubaria (Walker, 1919; 

 Kuehner, 1926, Lepiota (Atkinson, 1914), Myxoderma {Limacella,Lepiota) 

 (Kuehner, 1926), Pholiota (Sawyer, 1917) Rozites (Kuehner, 1926), 

 Psalliota (Atkinson, 1906, 1914, 1915; Levine, 1922), Stropharia (Zeller, 

 1914; McDougall, 1919), Amanitopsis (Atkinson, 1914, 1915) and 

 Panaeolus (Kuehner, 1926), the development of the fructification takes 

 place, as in the Tricholomateae, hemiangiocarpously. In Amanitopsis, 

 the blemmatogenous layer is differentiated into a true universal veil. 



The subfamily is divided into several parallel series, first recognized 

 by Patouillard (1900), which, however, in many respects are in need of 



