176 Transactions British Mycological Soctety. 
(3) The black rust of barley infected barley, rye and Couch 
grass but failed to infect wheat. This form is different from that 
on wheat and probably is identical with that on Couch grass. 
(4) As far as black rust is concerned specialization is not 
quite so fixed as has been recorded elsewhere. In this locality 
Couch grass infected with this rust may be a source of danger 
to barley. 
(5) The brown rust of rye is rigidly specialized to its host. 
(6) The brown rust of wheat casually infects rye. 
(7) The dwarf rust of barley and the yellow rust of wheat 
cannot infect other cereals. 
THE LITERATURE ON THE CLASSI- 
FICATION OF THE HYSTERIALES. 
By G. R. Bisby. 
The group of the Ascomycetes known as the Hysteriales is at 
present commonly considered to include a large number of forms 
characterized by fruit-bodies (known usually as perithecia or 
apothecia) which open tardily by a longitudinal fissure. The 
accretion of forms into this group is reflected by Saccardo, who 
gives, in volumes IJ, Ix, XI, XIV, XVI, XVII and XxII of the 
Sylloge Fungorum, seven hundred and three references to the 
Hysteriaceae and thirty-eight to the Hemihysteriaceae, included 
in a total of fifty-one genera. Eliminating duplicate, varietal, 
and revoked references, there remains a total of some six hundred 
and seventy species in forty-six genera in these two related 
groups in the Sylloge, and many species have of course been 
described too recently to be included. 
The writer has gone over the scattered literature in an attempt 
to set forth the ideas of classification held by various workers 
on this group. The knowledge of these fungi has, of course, under- 
gone much development during the past two centuries, but the 
Hysteriales are still comparatively poorly understood. 
Few early botanists devoted much attention to the fungi, 
and even when fungi were noted, the conspicuous forms naturally 
received first attention. The hundreds of Hysteriales, Pyreno- 
mycetes, Lichens, and other small, undescribed fungi which 
occurred in the woods and fields would either be unnoticed, or 
could be described only vaguely prior to the close of the 18th 
century. Certain Hysteriales and other fungi were included in 
