(JLVCOOF.N AND FAT. 169 



tho niiMt'W j,'rouj) of luu^'i. Tuliisiie seems not to have re- 

 collected the ohsei vutiuii of his nuHliciil colleii;;ue, since other- 

 wise he would hardly have contented himself with the liriefly 

 expressed hypothesis that a species of alhumin with a special 

 aHinitv for iodine was in (|uesti<Mi. The next worker in this 

 field, namely A. l)K I>auv(IV.) in 1S6}, enl:ir;(ed our insi;;ht 

 into the hot^inical siile of the question by the iinportjint dis- 

 covery that the suljstjince referred t<j d(»es not appear uniformly 

 distril>uted throu<;hout the plasma, hut is contini'd to one 

 portion thereof, which he proposed to call the epiplasma. At 

 the same time he expressed the opinion that the suhstiince in 

 question was a c.irl)()hydrate. Five years later W. KfEUXE (la.) 

 reported the occurrence of the '' matirre glycoijcne,"' or j,'lyco;rcii, 

 in At'tlt(tlinin sfjifimni. This discovery, however, did not atfoid 

 any certain proof of the appearance of fjlycogen in fun«;i, the last- 

 named organism beloni,'in^' to the Miji-fficnn ("^ 23), and there- 

 foie merely a connecting' link between the fun^i and the lower 

 animals. Up to that time no deiinite proof had been adduced 

 of the e.xi.stence of <,dycoj;en in vt-^'etible cells (those of funjji 

 in jtarticular), and therefore the term "animal starch, " applied 

 to this substance, was still in general use. 



It was not until 1882 that L. Eureka (11.), working in 

 A. de IJary's laboratory, showed the principal constituent of 

 fungoid epiplasm to be a carbohydrate, agreeing with animal 

 glycogen in all the properties examined by microchemicjil means. 

 He also demon.strated its wide distribution, not only in the 

 (first examined) da.ss of As<-i)iiiiireli\<, but also in the JifL^iiliomi/- 

 fffes anil the Mui-oi-(t<-<(r {\l\. and IV.). His di.scoveries were 

 confirmed by .severjil other workers, r.i/ \>\ Kkaekukk (I.) and 

 afterwards l»y E. Lai'KEXT (VI.). who found this carbohydrate 



also in Oidinm /a<i is, in tl 'uxdia ui C/Otlu.'^jjoriuiti Jieriniruiiif 



and in various rose yeasts. 



Of all fungi the yea.sts .seem to have been the most accunitely 

 examined with regard to their content of glycogen, and wherein 

 the metabolic importance of this carbohydrate has been mttst 

 clearly recogni.sed. Even for this rea.son alone, the ju'esent 

 appears the most suitable (K'casion for dealing witlj this con- 

 stituent of the fungi. Its microchemical detection jtresents no 

 ditlieulties, there being no other known cell constituent that 

 gives a .similar deep brown-red colorjition in presence of ioiline 

 and is tlu'iefore t-aiiable of lieint' mistaken for I'lvco^'en. Even 

 a beginner would not confound the relatively jwile yellow fur- 

 nished, under the same treatment, h\ the albuminous cell 

 constituents, with the fidl brown-red given by glvcogeti. 

 Should, however, any uncertainty prevail it may be dissipited 

 by utilising the ob.servjition first m.ide by Kiikeua (II.). to the 

 eiVect that if the pre)>ai-:ition be carefully wjirmed to 60' to 70° C 

 after the addition of the iodine, the \M\\e yellow due to albumin 



