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Botany. — Jon. H. van Burkom: “On the connection between phyl- 
ieee and the distribution of the rate of growth in the stem” 
(Communicated by Professor Went). 
(Communicated in the meeting of November 30, 1912.) 
Various investigators have studied the longitudinal growth of the 
stem. They have for the most part paid attention to the total 
increase in length of the stem and only a few investigated the dis- 
tribution of the rate of growth in one or several internodes. Com- 
plete investigations, on widely different plants with regard to the 
distribution of the rate of growth over the whole growing region 
have so far not appeared. There occur indeed in the literature two 
important utterances which are based on preliminary observations. 
The first is the opinion expressed by Sacus') that the growth of 
stems with distinct nodes differs from those with indistinet nodes. 
If the stem is sharply articulated then according to Sacus each 
internode shows its own curve of rate of growth. This rate increases 
from the base of the stem towards the apex, reaches a maximum 
and decreases again towards the upper node. If the stem has indis- 
tinct nodes then the whole growing region yields a single curve of 
rate of growth of this type. 
Rotaert *) has further described this. He speaks of individualised 
internodes when each internode grows as a separate unit and passes 
through the great period of growth, whilst in other cases the whole 
stem passes through this growing-period as one internode. Notwith- 
standing that these two authors have clearly distinguished two 
methods of growth, the growth of the whole stem in one growing- 
period has had most attention paid to it. so that in most text books 
it is given chief consideration. 
This is the circumstance which led me in 1907 to make measure- 
ments on various plants in the Botanic Gardens at Utrecht. 
With regard to the results of this inquiry which will be shortly 
communicated in my Dissertation, | wish here to make a brief 
preliminary statement. 
With the aid of a little stamj made tor this purpose or of a 
brush and India ink, linear marks were made on the stem, so 
that it was divided into zones. 
1) Sacus Jul. 1873. Ueber Wachsthum und Geotropismus aufrechter Stengel. Flora 
56 Jahrgang. Regensburg. 
2) Rornert W. 1896. Ueber Heliotropismus. Conn’s Beiträge zur Biologie der 
Pflanzen Bd VII. 
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