17, 6 Trelease: Salt Requirements of Wheat Plants 575 
‘RESULTS OF SERIES III 
Appearance of the plants.—The same kinds of top and root 
modifications described for series I and II were observed in the 
present series, with the exception of the longitudinal striping 
of the leaves and the phenomenon similar to “stooling,” which 
did not appear. Retardation of lateral roots was most pro- 
nounced in culture T2R1C1, but it was also severe in cultures 
T7R1C1, T8R1C1, and T9R1C1. Here also the color of the 
tops was seen to decrease in intensity in passing from left to 
right in the triangles; and all of the plants in the cultures of 
triangle 2 were greener than the plants in the corresponding 
cultures of triangles 7, 8, and 9. The forms of leaf injury ap- 
parently related to high partial concentrations of magnesium 
sulphate were observed in this series, and their distribution is 
shown upon the diagrams of fig. 8. In these diagrams the total 
number of leaves of the twelve plants grown in the duplicate 
cultures are indicated by the numerals placed near the points 
showing the location of culture solutions. Cultures marked by 
triangles showed severe injury; those marked by squares showed 
slight injury. 
Dry weights.—The actual dry weights, in grams, of tops and 
of roots, are given in Table 12. The dry weights of the plants 
of each of the two duplicate cultures and the average weights are 
shown. High yields are indicated in the table by the letter H; 
and low, by the letter L; the two highest yields in each triangle 
are considered high and the two lowest are considered low, for 
tops and for roots. The actual yields obtained at the same time 
with the T2R4C2 cultures are given at the bottom of the table. 
The data given in this table are shown diagrammatically in fig. 
7 (tops) and fig. 9 (roots). The method of plotting 1s some- 
what different from that previously employed; in this case high 
values are indicated by small triangles and low values by small 
squares, no attempt being made to indicate areas of high and low 
values. 2 
Water absorption—The data on water absorption for the 
cultures in this series are shown in Table 13, where the arrange- 
ment is similar to that in the preceding table. 
Water requirement.—The average amounts of water absorbed 
per unit of dry weight of tops and of roots are presented in the 
last two columns in Table 13. 
175542——4 
