1915] BROWN—PINUS STROBUS 231 
Elongation of aerial parts began in the young growth in question 
before May 3 and continued until about July 4. Assuming that 
growth before May 3 proceeded at the same rate as between May 3 
and May 30 (1.2 per cent a day), we can only infer that the awaken- 
ing of growth in length in the shoots began about 8 days before 
(April 25), a conclusion that field observation fully confirmed. 
Cessation of growth in length in shoots had occurred by July 4, 
without doubt because at this date the length of the season’s 
growth had surpassed that of the preceding year, and furthermore 
the terminal cluster of buds was fully formed. It follows from the 
data that in 50 young trees in 1913 elongation of the terminal shoots 
TABLE L 
GROWTH IN LENGTH IN THE TERMINAL LEADER 
Average Mean Per cent of 
Tits tbe} growth of | growth of | preceding | No. of |Per cent Pp pl ge 
growth : —— preceding | entier days gain | per day 
PC RNEAS re 1 ea aR ei20 ia ca 13.55 | “7 Nes, Cagis CO eae Sapna pares tae 
5 30-1013... :. $6 13.98 £3166 | 41.3 ay 1347.01 (ta 
SLT iro. Oe 13:22 13.55. | 93.9 ES 7.33.6 1.8 
~ 4-19T3. TA3y 13.45 12055 | I 19 9): 4272 Peng 
began in the last part of April and continued until July 4. What 
applies to the terminal shoot is even more applicable to the lateral 
branches where long growth is not as vigorous. Furthermore, 
the same relation exists between young and old trees. In the latter 
growth in length must have been completed by July 4, so that it 
may be concluded that in white pines in the vicinity of Ithaca, 
growth ceases during the early part of July." 
Before proceeding to a review of the results of others, perhaps 
a brief discussion of the elongation of the leaf is appropriate here. 
Only one observation was made in regard to this point, but for- 
tunately the date was July 4, so that it offers a chance for com- 
parison between growth of shoots and leaves. The leaves on the 
** MEISSNER (22) has noted the formation of ‘the so-called “Johannistriebe” in 
rare cases in white pine. Bud formation occurs in the normal way, but in such cases 
some buds continue growth the same year. This peculiarity has been noted in many 
ONE ROUNIE fruit trees, but is rare in conifers. 
