1018 
the maximum chanced to occur just under the node and was there- 
fore measured in the nodal zone, this zone showed the maximum 
growth. 
The ascent of the zone of maximal 
growth from the basal portion of the in- 
ternode now continued in the lowest zone 
of the second internode up to the maxi- 
mum rate of growth of this internode. 
In this case I found in both internodes 
one ascent of the rate of growth without 
diminution in or near the nodal zone 
(see fig. 3). 
Humulus lupulus Lixn. showed two 
Fig. 3. Sambucus niger Ling, different curves of the velocity of growth, 
11—16 Mei. namely, some had a regular course (one 
maximum for the whole growing zone) and some with a decrease 
at the upper end of some internodes. These divergent results can be 
brought into agreement by specially noting the movement of the 
maximum. | 
Its quick passage into the nodal zone, not only in the undermost 
growing internode but also in the second internodes, caused the 
curve of velocity of growth in these internodes to become a regu- 
larly ascending line. In the higher internodes the maximum occurred 
under the nodal zone. 
If a sufficient number of growing internodes had been marked on 
the same stem, I was indeed able to observe this. 
I think I have also observed that the movement of the growth 
maximum in an internode of Humulus takes place at about the 
same time as the maximum of the whole growing region is found 
in that internode. 
I regarded the growth as intercalary, if there was either in the 
upper or in the lower portion of an internode a short zone which 
maintained its growth a long time, whilst the middle of the internode 
was already full grown. 
I have observed intercalary growth in Commelina nudijlora LiNN., 
squisetum limosum Linn. and T'radescantia repens VAND. 
In Commelina 1 saw this stage preceded by growth throughout 
the whole internode with the greatest rate of growth below. The 
maximal rate did not, however, move towards the upper end but 
