no a t VoL - 6 



Jo4 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



found increased hydrolysis of starch by the enzyme, following 

 treatment with the anaesthetic. 



Butler ('13) observed, by means of the coloration produced in 

 slices of tubers by boiling them in Fehling's solution, and also 

 by analyses, the sugar content in potatoes during the rest period 

 and at the time of sprouting. He makes the statement that the 

 accumulation of sugar in the tubers has no particular physiolog- 

 ical significance as regards germination. He calls attention to 

 the fact that tubers which germinate at a relatively low tempera- 

 ture contain more sugar than those which germinate at relatively 

 high temperatures, and also that those which are allowed to 

 sprout in the soil have a higher sugar content than those 

 sprouted in the cellar. Certain sprouting potatoes examined by 

 him were found to contain no sugar, though the sprouts them- 



contained a considerable amount 



same 



after being stored in an ice chest i or 20 days, were found to have 

 accumulated a considerable amount of sugar, while the sugar 

 in the sprouts apparently remained constant. At the same 

 time potatoes taken from storage where the temperature had not 

 fallen below 6° C. showed considerable sugar in both tuber and 

 sprouts. His illustrations show that stored potatoes kept under 

 similar conditions were quite variable as to sugar content, some 

 not containing sugar at all or in the cortex only, others in the 

 medulla only, and still others in both cortex and medulla. 



According to some further results obtained by Butler, there 

 is less sugar in the vicinity of sprouting eyes than elsewhere, 

 and by analyses he found the sugar content of the seed ends of 

 sprouting potatoes to be small, as a rule, and to increase toward 

 the stem end. This is at variance with the results of Prunet 

 ('92), who found the greater amount of sugar in the seed end of 

 the tuber, and also with those of Appleman ('16), who found no 

 appreciable difference in the sugar content of the opposite ends 

 of those potatoes examined by him. 



Butler believes that the greater metabolic activity at the seed 

 end of the tuber, both during the rest period and at germination, 

 is unfavorable for an accumulation of sugar at that point, and 

 concludes from his data that there is "little if any translocation 

 from remote to budding parts, even in germinating potatoes. " 



