55 o 
Ingvar Jorgensen and Walter Stiles. 
As the season advances, the hexose sugars in the leaf increase 
in proportion to the sucrose, as the following table shows. 
Table XXXIV. 
Seasonal Variation of Sugars in Snowdrop Leaves. 
Date of 
picking. 
Time of 
picking. 
Max. shade 
temp. 
Per 100 g 
dry leaf. 
Sucrose. 
Sucrose. 
Hexose. 
Hexose. 
Feb. 16, 1906 
3 p.m. 
94°C 
19-8 
3-56 
1 
: 02 
,, 26, 1907 
4-5 „ 
7-2 „ 
15-07 
2-53 
1 
: 0-2 
Mar. 7, 1906 
3.30-4 p.m. 
194 „ 
14-55 
569 
1 
: 0-2 
,, 30, 1905 
5-6 „ 
96 „ 
15-5 
11*4 
1 
: 0-7 
Apr. 5, 1906 
4-4.30 p.m. 
15-6 „ 
14 64 
1117 
1 
: 0-8 
„ „ 1907 
» » 
14-4 ,, 
14-64 
11-61 
I 
: 0-8 
„ 24, 1905 
» 1 
10-6,, 
14-84 
17-29 
1 
: 1-2 
May 4, 1905 
3-3.30 „ 
n-7 „ 
10-3 
12-78 
1 
: 1-2 
Parkin considers that his results strongly support Brown and 
Morris’ view that sucrose is the first recognisable sugar to appear 
in the leaf, and that glucose and fructose arise from it by inversion. 
He also brings forward evidence in support of Brown and Morris’ 
contention that fructose is generally present in excess of glucose. 
Thus, out of 54 analyses, in 47 cases fructose was in excess of 
glucose, the proportion ^ u . ct0S( r varying from -i— to , while 
glucose 0’4 0-76 
in only 7 cases was the reverse the case and then the glucose was 
only slightly in excess, the fructose : glucose ratio varying from 
1 : 1*01 to 1 : P06. As there is a greater tendency for the fructose 
to be destroyed by the careless use of basic lead acetate, these 
7 results are probably due to experimental error. Parkin considers 
therefore with Brown and Morris, that glucose contributes more 
readily than fructose to the needs of the leaf. 
3. Mangold (Beta vulgaris, L., var. Sutton's Yellow Globe). 
Davis, Daish and Sawyer have attempted to obtain information 
in regard to the sugars in leaves and leaf stalks of the mangold at 
different times of the day and night and at different seasons by an 
extensive series of analyses carried out at Rothamsted. 
Collections of leaves were made from plants growing in the 
field at 2-hourly intervals over a 24 hour period. Such series of 
measurements were made at three different times. 
I. Stage of early growth. 6 a.m., August 26—4 a.m., August 
27, 1913. 
