514 Pieters. — Influence of Fruit-bearing on 
shoot the base is firmer than the apex. The interpretation of 
the term c weicher ’ to mean mechanically weaker as well as 
softer seems justified by a sentence from the abstract in the 
Bot. Centralblatt, as follows : c Bei den Kulturvarietaten 
bildet der Holzring einen kleineren Theik des Dickendurch- 
messers eines Zweiges als bei den Wildlingen. “ Kultur- 
varietaten sind weichholziger,” sagt die Praxis.’ The entire 
argument also tends to show that the thought in Sorauer’s 
mind was that a shoot on a cultivated tree was less able to 
bear mechanical strain than one on a wild tree. He tabulated 
his results to show the different percentages of wood and of 
cortex in the shoots examined. These percentages are in 
terms of the pith. No reason for using the measure of the 
pith as a basis is given in the abstracts, but there is one 
objection to this method which I wish to point out. The 
apparent difference in the relative amounts of wood in the 
different shoots is much greater than it would be were 
the percentages given in terms of the diameter of the shoot. 
Sorauer’s last table, in which he summarizes his results, will 
serve as an illustration : — 
Cortex. Wood. Pith 1 . 
Wild pear . . 75 % 80 % 100 % 
Cultivated pear . 91.4 % 58*2 % 100 % 
% 
This shows a considerable difference in the percentages of 
wood and cortex ; but, if the percentages are given in terms 
of the diameter, we have the following for the same shoots : — 
Cortex. 
Wood. 
Pith. 
Wild pear 
36.6 
39-6 + 
23 + 
Cultivated pear 
45 + 
29 + 
26 
The actual measurements from which all the above 
percentages were determined are as follows : — 
Wild pear 
Cortex. 
24-8 
Wood. 
27.9 
Pith. 
33-3 
Wood. 
2 5*4 
Cortex. 
25.2 
Cultivated pear : 
Base of intemode 
5 8 *7 
42 
67-3 
42.7 
7 2 ”3 
Middle of internode 
66.3 
4 i 
7 6 -5 
41*2 
65’5 
1 The pith is not in the original, but it is put here for the sake of clearness. 
