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nodes. That this really is not the case will clearly be shown by the 
further analyses, in which were examined, on the one hand resting 
buds, on the other etiolated shoots, both with the corresponding 
internodes. 
Resting buds —18. 2. 02. 80 buds Z. Padus (Bot. G.), and inter- 
nodes bearing them; weight: 8,80 gr.-HCN : 0,0121 er. ; 1. e. 0,14°/, ; 
me tO00250,0151 er. 
18. 2. 02. 125 buds and internodes; weight: 9,90 gr.-HCN : 
0,0159 gr. ; i. e. 0,16°/,; in 100: 0,0127 er. 
21. 3. 02. 100 buds and internodes (the buds beginning to open 
at the top for the greater part); weight: 8,35 gr.-HCN : 0,0092 er. ; 
ie. 0,11°/, ; in 100: 0,0092 gr. 
29. 3. 02. 127 buds and internodes (eut on other shrubs as the 
foregoing ; buds about to open); weight: 13,30 gr.-HCN : 0,0125 er. ; 
Loe, O09")? sin L00 + 0,0008 “er. 
Young shoots. — Branches placed in the dark 24. 2. 02. 
17. 3. 02. 30 shoots and internodes; weight: 11,75 gr. HCN: 
00144. er ie. 0,09°/, ; mi! 100: 00370 er. 
Branches in the dark 24. 2. 02.; 25. 3. 02. 25 shoots and inter- 
nodes; weight: 5,05 gr.-HCN: 0,0051 gr; ie. 0,10°/,; in 100: 
0,0204 er. 
The considerable increase in the quantity of prussic acid: two to 
three times the original amount, shows clearly that it has not been 
augmented in the shoots at the cost of the internodes immediately 
belonging to the buds. I can even go farther, and suggest that 
neither it can have been supplied by the more distant internodes, 
one year old. In the analyses of shoots with the adjacent internodes, 
as well as in the experiment with internodes only, the material was 
taken from twigs developed the summer before, which in the experi- 
ment had yielded shoots at different heights. Therefore, if the more 
basal internodes had furnished the HCN-material for the shoots nearer 
the top, then the estimations would have shown it, since in that case 
so great an increase as was noticed would have been impossible. 
If consequently during the growth of the young shoots prussic acid 
might be drawn from the branches, it could be only from the older parts. 
I should have liked very much to establish with certainty whether 
the shoots form themselves the hydrocyanie acid they contain. For 
that purpose I several times analysed branches of P. Padus as well 
as of P. Laurocerasus, so as to determine the amount of HCN pre- 
sent in the entire branches, before and after the opening of the buds. 
These estimations however did not yield satisfactory results, because, 
when the branches used were small, the buds in the dark only gave 
