278 BOTANICAL GAZETTE [APRIL 
The average weight of the shade plants was nearly 170 grams 
greater than that of the sun plants. Moreover, there was no 
aberrant case. The members within each group were fairly uni- 
form, but all of the shade plants had a greater weight than any of 
the sun plants. The distribution of the material within the plants 
is worthy of note. Here also the results, in whatever direction 
they point, are true as well for a comparison of the individual 
plants of the respective groups with each other as for a comparison 
of the general averages. The average weight of the leaves of the 
shade plants was 68 grams higher than that of the sun plants, 
while the difference in the stems was still greater, the difference 
here being over 100 grams in favor of the shade plants. The fresh 
weight of the root-systems of the two groups of plants was about 
the same in both. These relations are especially interesting when 
considered in connection with the weight and distribution of dry 
matter in the plants as shown in table IX. 
TABLE IX 
WEIGHT OF WATER-FREE SUBSTANCE OF PLANTS 
OPEN 
No. of plant Leaves Stems Roots Total 
Seow 
Oe ee 82.54 73.09 53.40 209.03 
en 67.36 59.72 41.25 168. 33 
Peer i Renn 75.01 69.71 47-19 by $id 
Re ee is 74.32 70.76 42.89 leeds 
re 74.35 67.62 43.99 185.0 
2 SARS ea ot! 73.40 71.05 43-75 sige 
Average... . 74.50 68.66 45.26 188.42 
SHADE 
en 
1 71.61 90.3 49.46 — 
7 Rp. 69.67 82.92 46.49 - 
Se es: 66 78.08 40.17 184. 7 
15 Sees 59 = 74.22 38.73 3 
ae ee getes 71.65 76.19 38.96 
BP 2 76.32 35.26 174-27 
Average....| i 66.94 ~ 79.68 ay et 188.14 
ae 
While the average fresh weight of the shade plants was nearly 
170 grams greater_than that of the sun plants, the average dry 
