227 



assume that old flasks always split off more alkali than new ones. 

 The flasks were stenlised by heatmg them on three consécutive 

 days to 100" for half an hour. The solutions of reducmg sugars 

 (glucose, maltose and lactose), which at first were colourless, be- 

 came Iight brown. I see the cause of this in the présence of the 

 alkali: probably it caused an enolisation, also giving rise to ketones, 

 according to the following équation 



R . CHOH . CHO ':Z R . COH'. CHOH ^ R . CO . CH^OH /o ■ , ^ 



(Boeseken) 

 aldosc enol ketone 



We must therefore re^ember, that in the séries of cultures on 

 reducing sugars, some of the sugar is always changed into other sub- 

 stances. AspergUlus niger forms enough acid on the first days to 

 neutralise ail the alkali: I therefore paid no more attention to it 

 Of course it would hâve been better to use Jena glass, but as there 

 were always 200 — 300 flasks in use, the available supply in the 

 laboratory would not hâve been sufficient. 



Hanna Lappalainen informs us too that there are cultures of 

 AspergUlus niger from ail parts of Europe in the laboratory of 

 professor Elfving in Helsingfors. Amongst thèse, their seem to 

 be eight vanaties, which differ physiologically from each other. 

 Brenner claims to hâve discovered three new ones. He compares 

 them to the mutations, which hâve been descnbed by Sçhieman n , 

 but in my opinion, he is not entitled to do so. Schiemann ob- 

 tained them by adding poisonous salts to the nutnent bases, while 

 Brenner obtained his bycultivating his fungi at différent températ- 

 ures for a very long time. The fungi are naturally influenced to a 

 very large extent, but if we allow them to grow in their original 

 environment long enough, they again assume their original quali- 

 ties. In this way he himself succeeded in getting back an old race 

 out of a mutation. 



The investigations of Lappalainen and Brenner were made 

 with a totally différent object in view than mme. They observcd and 

 descnbed différent physiological reactions and I am unable to say 

 which of the différent races of the fungus, descnbed by them, I 



