i 7 8 



The " Greening " of Potatoes. 



[JUNE, 



and had become thoroughly "greened," had lost barely three- 

 quarters of an ounce. Water probably accounted for most 

 of the loss of weight; respiration would also be responsible 

 for some loss; and the presence of sugar (Trommer's test) 

 indicated a certain amount of activity in connection with 

 growth. 



In the following experiments, the kind of potato, the 

 weight, and the duration of time were identical with those 

 mentioned in the first experiment. 



Experiment No, 2. — Both batches of potatoes were covered 

 with black paper during the first five months of the experi- 

 ment. During this period a certain amount of sprouting 

 took place, the sprouts of the two batches weighing 2| oz. 

 At this stage the two batches, after the removal of the sprouts, 

 were practically of equal weight. One batch was now 

 covered with black paper, and the other batch left exposed 

 to light, and in this condition they remained until the end 

 of the experiment. The sprouts produced by the batch 

 exposed to light averaged a quarter of an inch in length, 

 and weighed a quarter of an ounce. The sprouts of the 

 batch covered with paper averaged three inches in length, 

 and weighed ij oz. The batch of potatoes that 

 had been covered with paper throughout the experiment 

 weighed if oz. less than the batch that had been exposed to 

 light during the last two months of the experiment. 



Experiment No. 3. — At the commencement of the experi- 

 ment, one batch was covered with black paper and the other 

 batch left exposed to light. This condition of things lasted 

 for two months, when it was found that the covered batch 

 had lost 1 oz. in weight, and the batch exposed to light had 

 lost about 18 grains. From this stage both batches were 

 covered with black paper, and remained so until the end of 

 the experiment, when it was found that the batch that had 

 been protected from light throughout the experiment had 

 lost 3 J oz. in weight, including the sprouts, whereas the 

 batch that had been exposed to the light for the first two 

 months of the experiment lost just over f oz., including the 

 sprouts. 



The batch that had been protected from light throughout 

 contained a considerable amount of sugar at the end of the 



