Kleinere Mitteilungen. 13% 
in specified fluctuating variability than a property of the organism. The 
chance curve is in the first instance an expression of the organism itself, 
or rather, the occurrence of the curve of probability is in all cases governed 
by a definite property of the organism, so that such a curve is some- 
thing specific for such a plant. In this sense we have indeed the right, 
for the sake of simplicity, to consider such a curve a representation of the 
property itself. 
By this the study of fluctuation has come into new lines; and one 
begins to operate with it just as one has done for a long time with other 
qualities. One proceeds now to examine them in behaviour that has long 
been known respecting other properties. One of these behaviours, for 
example, is periodicity during the successive developments of the organs 
of one and the same plant. Thus I examined the periodicity of the 
fluctuating variability in the leaf measurement again and again in one 
and the same coffee plant. 
As is well known, the branches of this plant occur opposite each other 
in pairs. I measured the length and breadth of each leaf on every pair 
of branches, and so obtained as many groups of measurements as there 
were pairs of branches. The numbers so obtained, relating to each of 
such pairs, have been tabulated, and subsequently compared with each 
other. It then became apparent that several of the successive branch pairs 
yielded the like results; and that consequently the same may be included 
in still larger groups. Now these larger groups exhibited remarkable 
differences in variability, as may be observed in the following table I. 
This applies here-to a single tree. The measurements began at the foot 
and proceeded gradually towards the top; the table must also be regarded 
in the same way. The Roman numerals under the word “frequency” indi- 
cate the group of merely pairs. The cipher following, indicates the number 
of successive branch-pairs included in the group. The table has reference 
to a specimen of Coffea Uganda. The experiments were all conducted in 
the “Cultuurtuin” (Experimental Gardens), at Buitenzorg. 
Periodicity in the length of the leaves may indeed be constituted at 
the first glance; for, although width of variation may generally be an 
unreliable measure for variability, still in this case a comparison based on 
the width of variation is admissable, since the number of leaves in each 
group is about the same. Besides that the quartils are also reckoned (Q). 
Not only however does the frequentation of the leaf-length exhibit 
periodicity in the measure of length, but of breadth as well. In the follo- 
wing table II the frequentation of the leaf-breadth exhibited, is for the 
same specimen of Uganda as in table I. The branch-pairs are also here 
united in groups. These groups do not correspond with those of leaf- 
length, for which reason the groups are represented there by the letters 
A, B, C ete. 
