282 INDEX. 



Xanthin, preparation of, 176 Yeast-cells, nuclein prepared from, 88 

 ,, reactions for, 177 



derivatives of, 185 Zinc lactate, 126 



physiological action of, 186 sarcolactate, 127, 128 



Xanthokreatinin, 208 Zymogen, an antecedent of the enzymes, 



Xanthophane, 262, 265 55 



Xanthoproteic reaction for proteids, 7 of pepsin, 60 



Xanthopsin, 266 ,, of trypsin, 63 



Zymolysis, 52, note 



Yeast-cells, early observations on, 71, ,, phenomena of, 74 



72 ,, heat phenomena of, 75 



