June, 1922] 
MUENSCHER ABSORPTION OF SALTS 
be discussed later. If the salts in the solution enter the plant with the 
water and the entrance of the water is determined largely by the rate at 
which it is transpired, then, for a given concentration of salts, the greater 
the quantity of water transpired the greater will be the amount of salts 
brought in by the water absorbed. Burgerstein (1897) stated that a grow- 
ing plant must take up large quantities of water to supply it with the nec- 
essary inorganic elements. Sorauer (1880) and Thom and Holtz (191 7) 
suggested that the greater the concentration of the nutrient solution the 
smaller the quantity of it necessary to supply the plant with the necessary 
amounts of nutrient salts. Sachs (1887), Pfeffer (1900), and Jost (1907) 
implied a direct relation between transpiration and the absorption of salts. 
The data presented in table i do not bear out any direct relation between 
transpiration and the absorption of salts in barley plants grown in water 
cultures. On the contrary, the data indicate that the salts enter 
the plant independently of the rate of transpiration. 
Light-Shade Cultures 
Table 2 presents a summary of the data obtained from the cultures in 
which transpiration was reduced by shading. The shaded plants had 
slightly taller tops but were more slender and had fewer leaves than the 
plants growing in the open sunlight. The shaded plants stooled very little 
while the plants growing in the sunlight all stooled profusely. The roots 
of the shaded plants were much shorter and had fewer branches than those 
grown in the sunlight. The total green weight, dry weight, and ash weight 
were reduced to less than one half in the shaded plants. The shading not 
only reduced transpiration, but also reduced the photosynthetic activity of 
Table 2. Relation of Ash Content in Barley Plants to the Amount of Transpiratio?i as 
Afected by a Difference in Light I?itensity. Summer Series. 
Plants Grown 5 Weeks {August 4 to September 8, iq2q) 
No. of cultures averaged. . . 
Green weight per culture (grams) 
Dry weight per culture (grams) 
Total ash content per cultur 
(grams) 
Ash content (percentage of green 
weight) 
Ash content (percentage of dry 
weight) 
Total water transpired (cc.) .... 
Water used per gram dry matter 
(cc.) 
Water used per gram ash content 
(cc.) 
Light 
Shade 
Tops 
Roots 
Plants 
Tops 
Roots 
Plants 
12.42 
1-235 
4.41 
.2897 
25 
16.82 
1-525 
5-37 
-509 
1-83 
.085 
24 
7.20 
.5944 
.2335 
.0885 
.322 
.1036 
.0173 
.1209 
1.88 
2.01 
I.9I 
1-93 
•95 
1.68 
18.91 
30-55 
21.13 
833 
546.24 
2,586.95 
20.34 
20.35 
20.34 
400 
672.95 
3,308.52 
