36 TROWBRIDGE: THE THERMOMETRIC MOVEMENTS 
The measurement reported consisted in the change in height : 
of a branch of this species due to the growth and to the fall of the 
leaves. The height decreased in April and May, coincident with — 
the growth of the leaves. Then followed a period of rest, but in 
August and September there was a further depression. In Octo- ‘ 
ber, the branch rose with the fall of the leaves, the maximum ; 
variation being about one foot. “During the winter months, _ 
very little change in the elevation of the branch was observable, | 
as shown by the observations, etc.”’ No temperature changes werfe- 
recorded. It is seen that this paper does not relate to the problem q 
under discussion. a 
‘‘ An undescribed thermometric movement of the branches of : 
shrubs and trees,” by W. F. Ganong,* is in some respects closely 
connected with the work of Caspary and Geleznow and wi 
the observations made by the writer of the present paper. 
Daily Record HEIGHT OF BRANCH 
+ | oh ; 
5 — aah Branch Bo) 
. T 1 oN 
2S} & \ tf nN | | aes : 
3 | \ / \ | e Y Lin Be 
coke Mitt a ae 
Ly [ 
4 Tt fe 
70 \I) ~ 
7 \ : \ / k r 
<4 i 1 4 Temperature F | — 
i \ ? “reezing point of water [al 
5 . pay 'Fmil Ee 
PRs OER ies IE ai a 
60! stoeccahaaite MARCH ee 
3M 15 16 17 19 20 2) 232% 26 27 2829 | 2 1¢ 15 18 2 22 2925 262728 2930 ; 
Fic. 6. Daily record of the movements of Branch B, Tree No. 1 (Europeaa : : 
linden) during February and March, 1912. The movements correspond closely with 
those of Branch A, in Fic. 4, ipesigy: some of the observations were on differ 
ent days. . 
Ganong’s observations related mostly to the movements © 
twigs of shrubs and very small trees, and scarcely exceeded 1 
cm. There is no mention, moreover, of the important fact @ 
* Ann. Bot. 18: 631-644. f. 52-57. 1904. 
