. En 
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25 leaves (Noordwyk). 
Halves @: 20. 12/01. 0,0165 er: HCN. 
Halves 6: 7. 1. 02, (beginning to show yellowstreaks 
along the nerves): 0,0142 gr. HCN. 
20 leaves (Bot. G. Amsterdam). 
ere ate. Oa teh ow Te ORG oor: HEN: 
b: 9. 5. 02. (yellow patches) 0,0113 or, HCN. 
25 leaves (Noordwyk). 
OPOLE ver 0268 ore HON, 
b: 20. 1. 02. (yellow) 0,0089 gr. HCN. 
25 leaves (Bot. G. Amsterdam), 
mh keer cs). OO28S. Se CN: 
G: 20. 4 O2 (yellow) 00,0067 gr. HCN. 
Just the same processes can be observed, when cut branches bearing 
leaves are placed under opaque cylinders. The leaves can remain 
fresh and green many weeks, and keep their amount of HCN unal- 
tered. The halves « of the blades were analysed immediately ; the 
halves 6 remained, adhering to the middle-nerve, on the branches 
till the end of the experiment. 
25 leaves, from branches placed in the dark 5. 12. Ol. 
me ao OL. OCO2 ZOET iG: 
6: 22. 12. O1. 0,0283 gr. HCN. 
25 leaves, from the same branches (5. 12. O1 in the dark). 
31. 12. O1.; halves cut off; the other ones remain on the branches. 
a: 00,0243 er. HCN. 
b: 16. 1. 02.; remaining halves yellow ; it appears that in this 
stage they fall off, or sit but loosely on the branches : 0,0196 gr. HON. 
3ranches placed in the dark 17. 12. 01.; 
1. 1. 02.; 10 yellow leaves, about to be dropped; weight: 
17,65 er.-HCN: 0,0094 gr; i. e. 0,05 °/,. 
From the same branches I took the same day 25 fresh green 
leaves, and cut off the halves; weight: 13,15 er.-HCN: 0,0229 er, 
epee OT */ 
Halves 4; 14. 1. 02 for the greatest part yellow, and falling off 
— HCN: 0,0155 er. 
This experiment therefore is also of importance, because it shows 
how the diminution in the amount of HCN goes clearly together with 
the discoloration and dropping of the leaves, and does not directly 
depend upon the length of the stay in the dark. In fact, when I 
placed separated branches in the hot house, but exposed them to the 
light, there always were a certain number of leaves that became 
