┌────────────────────┬────────────────────┬───────────────────────┐ │ │ │ Relative Rates. │ │ Yeast. │ Mode of Culture. ├──────────┬────────────┤ │ │ Grown in: │ Glucose. │ Galactose. │ └────────────────────┴────────────────────┴──────────┴────────────┘ S. Carlsbergensis wort 100 <1 " hydrolysed lactose 100 86, 83, 85, " " " 25, 46, 51, " " " 69, 54, 155 S. Cerevisiæ wort 100 <1 " hydrolysed lactose 100 21, 26, 29 S. Thermantitonum. wort 100 <1 " hydrolysed lactose 100 77, 53, 35 S. Ludwigii wort 100 <1 " hydrolysed lactose 100 <1 ─────────────────────────────────────────────────────────────────── [p133] It will be seen that in one case the rate of fermentation of galactose was considerably greater than that of glucose. /S. Ludwigii/ did not respond to the cultivation in hydrolysed lactose, but, as Slator points out, it is quite possible that repeated cultivation in this medium might effect the change, and this would be strictly analogous to the results obtained with bacteria. Slator's results have been confirmed by Harden and Norris, R. V. [1910], and by Euler and Johansson [1912, 2] who have made an exceedingly interesting study of the progress of the adaptation. As in the case of mannose the rates of fermentation of glucose and galactose are differently affected by agents such as heat and alcohol; moreover, the rate of fermentation of mixtures of dextrose and galactose is in no case either the sum or the mean of the rates obtained with the separate sugars. The temperature coefficient of the fermentation of galactose also differs slightly from that of the other hexoses. ┌───────────────────┬────────────────────────────────────┐ │ │ Relative Rates. │ │ Yeast. ├──────────┬────────────┬────────────┤ │ │ Glucose. │ Galactose. │ Glucose + │ │ │ │ │ Galactose. │ └───────────────────┴──────────┴────────────┴────────────┘ S. Cerevisiæ 100 0 103 " 100 34 103 S. Carlsbergensis 100 155 119 S. Thermantitonum 100 76 124 ──────────────────────────────────────────────────────────