1017 
In Clematis alpina Miuier, Clematis recta LINN., Eucalyptus Glo- 
bulus LaBur., Dahlia variabilis Duss. Polygonum cuspidatum Sree. 
et Zuce, Polygonum Sachalinense FK. Scumipr and Sambucus niger 
Linn. the zones lying below the node had moreover a distinctly 
slower growth than the others. (See fig. 2). 
all || | 
“TELL LN \ LN iN i 
Wig. 2. Polygonum Sachalinense ¥. Scummr 9—11 May. 
In both groups of plants in the beginning the lowest part of each 
internode grew fastest whilst the rate of growth near the upper end 
decreased till in the ‘‘node-zone” it became very slight or zero 
(Polygonum). 
Afterward the maximal rate of growth was displaced toward the 
apex and diminished in magnitude. 
‘The zones in which the maximal rate of growth had lasted the 
longest time, during which period this maximum in the internode 
also reached its greatest value, increased much more than the upper- 
most zones in which the maximum lasted only for a shorter time 
and in which it was moreover munch decreased in intensity. 
The difference between the first group (Acer ete.) and the second 
group (Clematis ete.) lies in the rate at which the maximum of 
growth travels along each internode and the point of time at which 
it occurs. 
In the first group the displacement of the maximum begins in a 
very early stage of development and the maximum is very quickly 
found below the node. On the other hand this movement is slow 
in the plants of the second group, so that for some time, often indeed 
for a considerable time, the uppermost zones of an internode show 
less growth than the inferior zones of the same internode. 
Since the difference is confined to the moment of time in which 
and the velocity with which the maximum moves in the direction of 
the apex, the two groups are not sharply differentiated, and sometimes 
it is possible to obtain a curve of the rate of growth from plants 
in the one group which agrees with that from the other eroup. 
I have not yet been able to determine from my observations what 
factors may influence the movement of the growth maximum. When 
