(;ia'cu(;kn and fat. 173 



construction of new imlividiials ui»«l ft>e«liiig them until such 

 time as thev iire able to eater for tliemselves. This hitler t-vent 

 takes phice for insUmee when a sclerotium fi^erminates. In the 

 case of Cuj/nnun nirt'iin and Clat i'-tj>s }>ur/tun a, L. Kuukua (VI.) 

 accurately traced IIr* gradual migration of the glyo^gen from 

 the colls of those hard mycelia into the pileated fungi developed 

 therefrom. Ho also observed the same in the germiiiation of 

 various fungus spores, f.ij. those <tf Murnrcvfti-. This migration 

 of glycogen is tlu* counterpart of the well-known movement 

 of starch in higher plants, especially during the germination 

 of their seeds. With regard to this worker's report on the 

 formation of glycogen from the oil in the cells, further observa- 

 tions are desirable. 



The degradation of glycogen for the genenition of energy 

 may either remain only half accomplished, as we shall see in 

 greater detiiil in a subseipient paragraph dealing with the auto- 

 fermentjition of yea.st, or may proceed until the whole is com- 

 pletely ct)nsumed into carbon dioxide ami water. So far as is 

 known, this condition is reached in the case of yeast cells, when 

 the acce.ss of air is unrestricted. Cells of wine yeast that have 

 fallen to the ground, keep alive, thanks m.iinly to their store of 

 glycogen. It does not always happt-n, however, that the cell> 

 are able to use up this store, since they .sometimes perish befoie 

 the same is exhau.sted. According to the observations of II. 

 Will (X.), dead permanent cells rich in glycogen can always 

 be found in the sedimental yeast of old cultures in wort or 

 (liquefieil) wort gelatin. Finally it may bo rem.irked that the 

 commencement of the working up of accumulated glycogen 

 does ni»t always coincide witli the occurrence of a lack of the 

 nocessiiry foodstuUs outside the cell, but seems to be bound up 

 with other circumstjinces, the age of the cells in particular ; 

 so that the glycogen content of a .sjimple of ywist may decline, 

 although sugar is still pre.'^ent in the nutrient solution. In this 

 connection observations have been made by N. Jouluaikk (1.) 

 in the cour.so of some researches which will be referred to in a 

 later section; and these were conlirmed by ( Jontscharuk, who>e 

 results have been reported by 1{. Mkissnkk (ill.). 



The importance of fats for the life of the yeast cell is equal 

 to that of {jlvcoyen ; they al.so are valuable reserve material. 

 Their presem-e in wine sediment was observed by l?raconnot. 

 Till' percentjige of fat varies with the monu'nt;iry conditions nf 

 nutrition of the cells. Payex (11.) fixed it at 2.\ per cent, of 

 the dry residue in the case of beer yeast; but, by the aiil of 

 a better metlunl, ensuring complete extniction, N.KUKLi and 

 LoKW {\\.) succeeded in separating about 5 per cent, of fat 

 from a bottom-fermentition beer yeast. Acconling to the 

 researi'hes of P. Dauf.xv (I.), alone, and in collabiiration with 

 E. (Jkkakd (I.V the cliief constituents of yeast fat are steaiii- 



