150 ] The Classification of Lower Organisms 



lina by a line of descent separate from those which have produced the holobasidia of 

 other groups. By leaving Tulasnella in order Tremellina, we spare ourselves the recog- 

 nition of one more insignificant order. 



Order 5. Dacryomycetalea [Dacryomycetales] Gaumann Vergl. Morph. Pilze 490 

 (1926). 

 Suborder Dacryomycetineae Engler in Engler and PrantI Nat. Pflanzenfam. 

 ITeil, Abt. 1**: iv (1900). 



Saprophytic Basidiomycetes producing small gelatinous fruits bearing holobasidia 

 in which two of the nuclei produced by meiosis undergo degeneration, while two 

 pass into the basidiospores by way of stout sterigmata which give the basidium the 

 form of a Y. Conidia are produced either from the mycelium, from the young fruits, 

 or from the basidiospores. 



There is a single family Dacryomycetacea [Dacryomycetaceae] Hennings in Engler 

 and PrantI Nat. Pflanzenfam. I Teil, Abt. 1**: 96 (1900). Dacryomyces, Dacryomi- 

 tra, Guepinia. Bodman ( 1938) observed the details of the cytological processes in the 

 basidia. 



This insignificant order, like Tulasnella and the two great orders next to be con- 

 sidered, is evidently derived from Protobasidiomycetes, through Tremellina, by loss 

 of septa in the basidia; the peculiarities of its basidia suggest an independent origin. 



Order 6. Fungi L. Sp. PI. 1171 (1753). 



Order Hynienothecii Persoon Syst. Meth. Fung, xvi (1801). 



Class Hymenomycetes and orders Pilcati and Clavati Fries Syst. Myc. 1: 1, 2 



(1821'). 

 Yzmily Hymenomycetes Fries Espicrisis 1 (1836). 

 Family Agaricaceae Cohn in Hedwigia 11: 17 (1872). 

 Order Hymenomycetes Winter in Rabenhorst Kryptog.-Fl. Deutschland 1, Abt. 



1: 74 (1884). 

 Suborders Exobasidiineae and Hymenomycetineae Engler in Engler and PrantI 



Nat. Pflanzenfam. I Teil, Abt.'l**: iv (1900). 

 Orders Hymenomycetales and Exohasidiales Bessey in Univ. Nebraska Studies 



7: 307, 308 (1907). 

 Order A^aricalcs Clements Gen. Fung. 102 (1909). 



Orders Cantharellales, Polyporales, and Agaricales Gaumann Vergl. Morph. 

 Pilze495, 503, 519 (1926). 

 Basidiomycetes producing holobasidia in a layer which is or becomes exposed to 

 the air, usually on fruits which are woody, leathery, or fleshy, rather than waxy or 

 gelatinous. 



The layer of basidia is called the hymenium. In the lowest members of the group, 

 the hymenium is formed directly on the mycelium, on the surface of the host or 

 substratum; in higher examples, it is formed on the surface of more or less compli- 

 cated fruits; in the highest, it is formed in closed fruits which open to expose it. The 

 area of the hymenium, and the number of basidia it can bear, is increased when it is 

 not smooth, but thrown into teeth, ridges, plates, or other projections. Families have 

 been distinguished chiefly on the basis of the form of the hymenium. The system is not 

 reliably entirely natural; Overholts (1929) pointed out various microscopic details 

 which promise to contribute to a more natural system. Among these are cystidia, 

 swollen cells imbedded in the hymenium and projecting from it; in some examples at 



