272 DIVISION II-—COURSE OF DEVELOPMENT OF FUNGI. 
cylindrical form, and not unfrequently grow into long “septate hyphae. But many 
remain of a smaller size, and these together with their secondary sprouts may easily 
be mistaken for Saccharomyces. 
The other Fungi enumerated above, with the exception of those which are classed 
with Saccharomyces, agree with Dematium under favourable conditions in forming 
hyphae; for this fact the names of the observers given above are a sufficient 
guarantee. 
Secondly, among these sprouting Fungi some species have the power of exciting 
alcoholic fermentation, others have not. Both kinds are found even in the genus 
Saccharomyces ; S. Mycoderma, the flowers of wine, usually belongs to the second 
category, the other ascogenous forms to the first ; of the species, which as far as we know 
at present do not form asci, S. apiculatus belongs to the first category, S. glutinis, Cohn* 
to the second. .Mucor racemosus is an inciter of fermentation when it developes the 
sprouting form. E. Hansen? has recently studied two forms, not yet certainly 
determined but resembling Saccharomyces, which are powerful fermenting Fungi and 
are developed from the hyphae of a mycelium. Most of the other sprouting forms 
mentioned above either excite no alcoholic fermentation or only a trace of it. The 
former is the case, for instance, with the sprout-cells of Exoascus Pruni, Dematium, 
and Fumago, which are very like those of Saccharomyces, and may be affirmed of 
most of the other species in the absence of any statements to the contrary. Sadebeck 
found signs of the formation of alcohol in the case of Exoascus alnitorquus. 
Thirdly and lastly, alcoholic fermentation is not confined to the sprouting form ; 
some species can excite it in the hyphal form also. Mucor racemosus is an instance 
of this and Eurotium Aspergillus glaucus also, according to Pasteur %. 
If we consider that these various matters were not originally kept separate from one 
another, and that, as has been already said, really distinct species were often enough 
mixed up with one another, we see an explanation of the protracted disputes mentioned 
above, and we need not enter upon any long account or critical examination of 
them in this place ; these will be found in the publications cited on page 127, and in 
the works of Reess, E. Hansen, and Pasteur on Saccharomyces and yeast mentioned 
below, as also in the first edition of the present book. We shall arrive even in the 
present day at very different conclusions, according as we understand the word Yeast- 
fungus to mean the sprouting form, or the exciting cause of fermentation, or Saccharo- 
myces in particular; but then our disputes become only a contest about words. From 
this point of view we must criticise the confusion which Brefeld has recently tried to 
introduce into the history of the ‘ Yeast-fungi.’ He has done good service by proving 
that the sprout-form is more general than was supposed, but then he proceeds to mix 
all the sprout-forms together under the name of yeast; moreover since some sprout- 
forms, those for example of Exoascus, may according to their position in the course of 
development be conveniently termed the spores or gonidia of Fungi which form 
hyphae, he transfers this designation under the name of ‘conidia-fructification ’ to 
all his Yeast-fungi, that is to his sprout-forms. In doing this he forgets or misunder- 
stands the facts at present known about Saccharomyces of which an account has 
been given in the preceding pages, and to which we must adhere so long as no new 
ones are put in their place. 
Literature. 
1. Papulaspora and Helicosporangium. 
E1paM in Cohn’s Beitr. III, p. 411, t. 13. 

! This name may be given to a rose-coloured form growing on boiled potatoes, which answers 
to Cohn’s description (Beitr. I, p. 187). 
? Bot. Centralblatt, 1884. 3 Etudes sur la biére, p. 100. 
