A BIOLOGICAL NOTE ON THE SIZE OF EVERGREEN 
NEEDLES. 
EDWIN BINGHAM COPELAND. 
THE profound influence which a prevalence of favorable or 
unfavorable weather in any season exerts upon the growth of 
stems is a matter of universal observation. Inadequate nutrition 
of the plant may be expected, and in general will be found to 
find expression in a more or less stunted development of both 
internodes and leaves; though in individual cases this parallel 
influence may be concealed by the different response of the 
two members to variations in light or moisture, acting as 
stimuli, 
The best specific instance, with which I am acquainted in 
literature, of the effect of imperfect nutrition upon the growth 
of leaves, is in a brief note by Reinke,’ who measured, on young 
trees of a number of species of Pinus and Abies, the length of 
needles formed (a) the year before the trees were transplanted, 
(4) the year when they were transplanted, and (c) the second 
year thereafter. In consequence of injury to the roots during 
transplanting, the needles formed during that year were mate- 
tially shorter than those of preceding or following seasons. 
Gregor Kraus? observed that the length of the needles 
Varies from year to year} under the influence of “Boden und 
Klima,” and mentions several instances: as one, in which the 
size of the leaves of deciduous trees is affected by the different 
illumination of different parts of the tree; and another in which, 
"Berichte d. d. bot. Gesells. 2: 376. 
*Abhandl. d. naturf. Gesells. zu Halle 16: 363. 1886. 
‘bid. 365. “Die absolute Linge der Nadeln eines Triebes hangt mit der 
Kraftigkeit des Jahrestriebes iiberhaupt zusammen. In giinstigen Jahren werden 
ekanntlich sehr lange und kriftige, in ungiinstigen viel kleinere und schwachere 
Triebe Sebildet, und die Kriftigkeit ocer Schwachlichkeit gilt nicht bloss fiir die 
Achsen, sondern auch fiir die Blatter.” 
1898] 427 
