174 BOTANICAL GAZETTE [AUGUST 
planned so as to include 3 series of experiments. In the first series samples — 
of freshly dug potatoes were collected and cut lengthwise aba two equal parts. 
One set of the samples was used immediately for the d of moisture, 
sugar, and starch. The corresponding halves were divided into 3 sets and each 
set stored at a different temperature for 12 days before similar determinations 
were made. The samples were stored at 30, 15.5, and 5°C. For a checka 
number of whole potatoes were subjected to the same conditions. The second 
series was a duplicate of the first, except that the potatoes were dug about 2 
weeks later. This series would show any change occurring in the growing 
potatoes after the first series was harvested. The third series of experiments 
was modified so as to determine the effect of removal of the vines on the carbo- 
hydrate transformations. The roots were not harvested until 10 days after 
a killing frost. 
HASSELBRING and HAWKINS pointed out that t to the rate of carbohydrate 
transformations in stored sweet potatoes the Van’t Hoff temperature law was 
applicable. In general, at 30° C. starch hydrolysis was rapid at first and soon 
reached an end point. At 15°5 C. a more normal rate of transformation took 
place, tending toward a state of completion. The hydrolysis at 5° C. was 
markedly retarded. In spite of the utilization of reducing sugar in respiration, 
HasSELBRING and Hawxrys were able to show a marked accumulation at 
first and very Bite ——— accumulation. The concentration of the 
F y luring the p Storage: 
‘There w: was a a lagi in iais bi ease chee accel with the increase of 
reducing sugar. The data suggested that the mode of carbohydrate trans- 
: formation in stored sweet potatoes was from starch to reducing sugar, which 
resulted in the formation of cane sugar as the end product. On studying the 
effect of eee it was found that during their activity 
the sugar content remained low. As as checked 
by removal of the vines, the usual f . bo 4 a. fcwcts 
‘potatoes manifested themselves. ; 
es _HASSELB SSELBRING and Hawkins" have coused out that tbe internal changes 
; storage must play an important réle in susceptibility to decay. Aside 
poe the theseetical Uipnificance, it seems that this mode of attack on storage 
" Problems of this nature will be of economic value—Frep W. GEISE. 
a 
_ Taxonomic selon SarsTO = in continuation of his studies of West a 
| en @, Passifora @), Rondeletia (10), Eriocaulon G)» Dupatya, Pilea, — 
Ichthyomet} , Castelaria, and Stenostomum | 2). a 
