210 BOTANICAL GAZETTE [MARCH 
the opening of the buds and the formation of new leaves. With 
this point in view, measurements were made on a young white 
pine stand of natural origin on May 3, 1913. The trees varied 
in age from 4 to 11 years and were in a thrifty, vigorous condition. . 
On this date the buds were found to have opened and the young 
stems to have elongated 0.5—2.5 inches. All the growth in length 
had occurred in the preceding 10 days. Neighboring trees which 
were older showed less pronounced elongation of young parts; 
but growth had been in evidence in older, less favored trees since 
March 29, 1913, and cell division at least since April 20 of the same 
year. It follows, therefore, that growth in thickness begins before 
growth in length, and apparently, at the start at least, at the cost 
of reserve food material. No correlation exists between the two 
in white pine. 
Concerning the time of cambial awakening, the researches 
of others bear out the conclusions of this paper. Some of CHRIS- 
TISON’S (5) are given in table E. It should be noted, however, that 
CHRISTISON’S results were obtained from bark measurements and 
do not necessarily indicate xylem formation. 
TABLE E 
GROWTH AWAKENING IN CONIFEROUS SPECIES, EDINBURGH, SCOTLAND 
No. of tree Name Year Awakening of growth 
BG ae Abies Lowiana 1890 April 
Ofer ce ...| Abies Lowiana 1888 Apel 16-30 
oR eee ne Abies Douglasii 1890 April 20 
Oe, oe ee — Douglasii 1888 April 16-30 
Co ee Abie 1890 April 13 
Pee ee a east excelsa 1890 a : 
Oe a ie aie Pinus Pinaster 1890 y 
WR eee Cedrus africana 1888 ree 1-40 
1p | : ae as 
MISCHKE (24) also made observations on this point, but did 
not include white pine among the species investigated. WHIELER 
(39), however, examined three white pines in his experiments of 
1894. Two of these were from a closed 40 year old stand, the third 
a 15 year old tree from another stand, all near Dresden, Germany. 
Growth was in evidence in the younger specimen to the extent of 
13 or 14 tracheids on April 24. No growth occurred at the base of 
