* 
232 BOTANICAL GAZETTE [MARCH 
terminal shoot of the season were compared with those of the pre- 
ceding season as to length (not thickness), and the results tabulated 
in table M in inches. Only 6 trees were examined, so that we can- 
not expect the uniformity that more extended observations would 
offer; still, the results are of value in that they lead to a general 
conclusion. 
TABLE M 
TABLE OF LONG GROWTH IN NEEDLES 
NEEDLE LENGTH AVERAGE 
DATE a ne DIFFERENCE PERCENTAGE sareastall 
7-4-1913.... 3-75 2.38 137 63 63 
7-4-1913 2.75 1.75 100 63 63 
7-4-1913 2.88 2 88 69 63 
7-4-1913 2.88 a1 75 73 63 
7-4-1913.... ¥.95 ae a3 62 41 63 
7-4-1913.... 2.38 r.75 63 73 63 
Elongation in the needles had not ceased on July 4; in no case 
was it three-fourths completed, as a reference to the table will 
show. Assuming that elongation in the needle is contemporaneous 
with elongation in the shoots," that is, that it began on April 26, 
it follows that during a period of 69 days the needles had attained 
on an average 63 per cent of the average growth of the preceding 
season. Assuming again that the rate of elongation was the same 
during the rest of the season, we may compute roughly the period 
necessary for the needles to complete their growth, that is, growth 
in length in the needles would be completed about 40 days after 
July 4, that is on August 13. It is reasonable to assume from the 
data on the 6 trees that the elongation of white pine needles ceases 
somewhere about the middle of August. 
If we correlate the results given above with those which have 
been previously given, we arrive at the following interesting 
conclusions for white pine in the vicinity of Ithaca. Growth in 
thickness (secondary thickening) begins in white pine before the 
elongation of aerial parts, either of shoots or needles. Elongation 
of shoots and needles begins simultaneously. The elongation of 
é 
5 Field observation substantiated this assertion. 
