MELIBIASE. 529 



made by other workers, an exhaustive report having been fur- 

 nished by W. HENNEBERG (IV.). The low-fermentation yeast 

 investigated by the latter and found to assume top-fermentation 

 characteristics in a remarkable and constant manner, fermented 

 melitriose completely ; and as it also fermented melibiose, it con- 

 sequently retained the characteristic property of low-fermentation 

 yeast as well. The question therefore arises whether such top 

 yeasts as ferment melibiose were originally low-fermentation yeasts 

 that have acquired top-fermentation characteristics spontaneously 

 and have retained them owing to the conditions of cultivation. 



The extensive group of wine yeasts, together with the lactic 

 acid yeasts, do not ferment melibiose. Lindner found that this 

 sugar was attacked by Diirkheim No. 54 yeast and Kiister Tokay 

 yeast No. 534. However, since these yeasts are no longer 

 cultivated and no further tests with them are possible, they should 

 be struck out of the scientific literature. With the foregoing 

 exceptions, all the races examined by SCHUKOW (I.), BAU (XXVI. 

 and XXVII.) and LINDNER (XXXV.) were found to contain no 

 melibiase, though KALANTHARIANTZ (I.) found wine yeasts that 

 were capable of splitting up melibiose. In one of these races, 

 from Bari in Apulia, a decided hydrolysis of melibiose was 

 observed on digesting the solution of the sugar with the yeast at 

 40 C., though no such action took place at 25-3o C. Assmanns- 

 hausen yeast also hydrolysed melibiose powerfully at 25 C. ; 

 but in view of LINDNER'S (XXXV.) statement that this yeast 

 has no action on melibiose, the report of Kalanthariantz needs 

 confirmation. 



Of the wild yeasts that have bean accurately defined in a 

 botanical sense, tiacch. Paslorianus I. and ///. ferment melibiose. 



A special position is occupied by Logos yeast (see p. 276, vol. ii.), 

 which, according to BAU (XV.) and SCHUKOW (I,), does not 

 ferment melibiose, though LINDNER (XXXV.) obtained a different 

 result. According to the results obtained by BAU (XXVI. and 

 XXVII.), there are two races of this yeast, one of them fer- 

 menting melibiose, whilst the other does not. Similiar race 

 divisions occur in the case of Schizos. octos2)orus, and Manilla 

 variabilis, and especially Torula colliculosa (see p. 398, vol. ii.). 



Summarising these investigations, it appears that, with the 

 exception of Grafenthal No. 389, all the culture low-fermentation 

 yeasts ferment melibiose, as do also two high-fermentation culture 

 yeasts, namely Liegnitz a No. 405 beer yeast and Winterhude 

 pressed yeast Race III. No. 139, Sacch. Pastorianus I. and ///., 

 two yeasts from Danzig Jopen beer, No. 600 and No. 603, a 

 number of unnamed wild yeasts and one race of Logos yeast. 



According to H. GILLOT (V.), melibiose is also left unattncked 

 by top-fermentation yeasts when readily assimilable sugars, such 

 as grape sugar, are presented to the yeast at the same time. 



I'AU (VIT.) based ;i method for detecting the adulteration of 



