276 Harris, GORTNER, AND LAWRENCE: 
j 1 
Sample | Height A F « X 10° x/A X 108 
. 
Robinia Pseudacacia L. JUNE 18, 1914 
1.158 
I.045 
13.93 | 1,512 | 1,306 
BR Pee 41 
| 12.57 | 1,589 | I,521 
18 
Robinia Pseudacacia L. JUNE 14, 1915 
* ap rene rae 40 1.189 14.30 1,379 1,159 
Ms Ager ae ets 28 1.126 13.55 1,407 1249 
Cini a I4 } I.017 12.24 1,213 1,193 
Robinia Pseudocacia L. JUNE 8, 1915 
Marne ae ge | 30 -876 10.54 | 1,061 | t,ar2 
as statees 13 -817 9.84 1,390 1,701 
Robinia Pseudacacia L. JULY 30, I915 
f Maen pases = 1.009 £2.34 1,390 1,377 
IB eae aes 25 -960 | T1.55 1,424 1,483 
(alas 8 -998 12.01 ,208 1,301 
Salix sp. JUNE 8, 1915 
| 
ae a | 25 | 1.029 \ 12.38 1,605 | 1,560 
haces 10 1.024 12.32 1,599 1,562 
Salix sp. JUNE 8, 1915 
Pe Seas | 33 | 1.180 | 14.20 1,567 1,328 
BB Sik oa aes 12 V.2FE 14.09 1,574 1,344 
Thus the signs are positive when osmotic concentration increases 
with height of insertion. 
For example, in the case of Acer rubrum of June 10 te . differ- 
ences are: 
Heights Tod A | P «XK 108 | K[AX 108 
A= Boos 20 0.026 | 0.31 — 48 48 
AU 6 oe. 35 0.051 0.61 — 75 80 
Ss eed Cag Ge 1s 0.025 0.30 — 27 — 32 
It is quite unnecessary to burden these pages with the actual 
differences, which have been represented graphically in the dia- 
grams. Summarizing the results we note first of all that in 73 of 
the 78 comparisons which may be made, the sample of tissue 
collected at the higher level shows a greater concentration than 
does the one take at the lower level. More satisfactory evidence 
