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 formasci, S. apiculatus belongs to the first category, S. glutinis, Cohn J 

 to the second. Mucor racemosus is an inciter of fermentation when it developes the 

 sprouting form. E. Hansen 2 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 8 . 



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. 



I. Papulaspora and Helicosporangium. 

 ElDAM in Cohn's Beitr. Ill, p. 411, t. 13. 



1 This name may be given to a rose-coloured form growing on boiled potatoes, which answers 

 to Cohn's description (Beitr. I, p. 187). 



2 Bot. Centralblatt, 1884. 3 fctndes sur la biere, p. 100. 



