150 
sugar had taken place to so high a degree that the tur- 
ning-angle of the plane of polarization was altered. As 
is well known, the solution of cane-sugar is right-tur- 
ning. The more cane-sugar inverted the smaller the 
turning-angle and at last the solution becomes left-tur- 
ning. In the case of the above mentioned polarization 
apparatus, where the percentage of sugar is directly red 
on the scale, the inversion is seen from the negative 
value obtained. 
The bored roots were kept during winter in a cellar 
used for roots. When examined in spring, before the 
planting, all the roots of Parisian carrot and Nantes were 
found to be rotten. The same was the case with most 
roots of Guer ancle; only a few of them were quite sound. 
Most of St. Valery’s had wintered in good condition; 
only a few were spoiled. 
St. Valery with the highest percentage of sugar was 
also the most resistant sort; Nantes with the lowest and 
Parisian carrot whith a negative sugar percentage sho- 
wed poor resistance. Guerande was intermediate in both 
cases. This behaviour seems to point to a certain re- 
lation between the power of resistance to rot during 
winter and the percentage of sugar obtained by pola- 
rization. 
The trial, however, did not give any information of 
the true percentage of sugar in the sorts. It might be 
very possible that the total sugar content was about the 
same in Parisian carrot and St. Valery , for example, 
but that it was inverted in much higher a degree in 
the first mentioned sort; this would also explain the lo- 
wer value of this sort. If this is the case, it would not 
be the higher percentage of sugar which influenced the 
degree of rot resistance; this would be explained by the 
greater or lesser degree of inversion of the cane-sugar. 
Not until last winter it has been possible to con- 
tinue these investigations. I deemed it well to make 
