The Literature on the Classification of the Hysteriales. 187 
other workers, down to the middle of the 1gth century, including 
Fries, placed the genera now classified in the Hysteriales with the 
Phacidiales. The genera came finally to be distinguished princi- 
pally on the basis of the colour, shape, and septation of spores. 
There has always been confusion in the use of names to 
distinguish orders, sub-orders, families, etc.; indeed, the same 
name is sometimes used by a writer in two senses: see Corda’s 
arrangement. Several mycologists (Saccardo, Spegazzini, von 
Hoehnel (76), and others) include all the genera in one family; 
if von Hoehnel’s contentions that Dichaena should be placed in 
a separate family, and that the Hypodermataceae, Ostropaceae, 
and Acrospermaceae all belong elsewhere, should be followed, 
only the family Hysteriaceae is left of those now usually 
(64, 67, 7x) included in the order. 
The Hysteriales have been placed in the Pyrenomycetes and 
Discomycetes about equally commonly, which indicates clearly 
that they form a transitional group; Rehm (67) compromised by 
placing them intermediately. Certain genera have likewise 
undergone a great amount of shuffling; the most conspicuous 
example being Acrospermum (which Tode (rs, p. 8) described as 
“Fungus simplicissimus’’!), which has been placed, as noted 
herein, in Clavaria, Sclerotiaceae, Tremella, Phacidiales, Hysteri- 
ales, Pseudohysterineae, Sordariaceae and recently by Riddle 
((78) agreeing with Ellis and Everhart) in the Hypocreales. The 
most recent tendency is to reduce considerably the number of 
genera included in the Hysteriales. 
Pycnidial stages, attributed to the Hysteriales, have been 
noted by certain workers (54, 64); these are usually hysterioid in 
nature, and include Leptostroma and Psilospora. 
Many workers not mentioned herein have described species, 
extended the knowledge of the distribution, or added other data 
regarding the Hysteriales. It is obvious, however, that the 
group is still in need of comparative and synthetic study. 
LITERATURE. 
(1) Ray, Joun.—Synopsis methodica Stirpium Britannicarum, etc., Ed. 111 
(1724). 
(2) Micuett, P. A.—Nova Plantarum genera (1729). 
(3) DiILvLEeNtius, J. J.—Historia Muscorum (1741). 
(4) Haier, ALBRECHT von.—Nomenclator ex Historia Plantarum indige- 
narum Helvetiae excerptus (1769). 
(5) LinnarEus, CARL.—Flora Suecica (1745). 
Species plantarum (1753). 
(7) LicHtTFoot, JounN.—Flora Scotica (1777). 
(8) WiGcGErRs, FRIEDRICH H.—Primitiae Flora Holsaticae (1780). 
(9) HoFFMANN, GEORG FRANz.—Enumeratio Lichenum iconibus et descrip- 
tionibus illustrata (1784). 
(10) BuLLIARD, PIERRE.—Histoire des Plantes vénéneuses et suspectes de la 
France (1784). 
