558 The Philippine Journal of Science 1920 
between the water requirement of roots and the dry weight of 
roots. Likewise, there is, in the present results, a tendency for 
the water requirement of roots to be inversely related to water 
absorption. There appears to be little or no relationship between 
the water requirement of roots and either the dry weight or the 
water requirement of tops. 
SERIES II 
METHODS OF SERIES II 
This series was conducted for twenty-four days, from Feb- 
ruary 12 to March 7, 1916. The highest temperature recorded 
during this period was 28° C. (February 14, 22, 28) and the 
lowest was 10° C. (February 13). The average daily maximum 
temperature for the period was 25°, and the average daily mini- 
mum was 16° C. The corrected water loss from the spherical 
porous-cup atmometer showed a daily mean of 17.5 cubic centi- 
meters and a total loss of 241 cubic centimeters for the entire 
period. This series was carried out in duplicate, so that there 
were two simultaneous cultures of six plants each for each of 
the sets of salt proportions tested. 
The plan of this series was similar to that followed for series 
I. The same four salts were employed and the solutions also 
had the same total osmotic concentration (1.60 atmospheres) 
as before. In series II it was planned to cover the range of salt 
proportions used in series I without repeating all of the cultures. 
Forty selected solutions were used. Their composition may be 
represented by the same kind of diagrams as were used for 
series I. The numbers and positions upon the diagram of these 
selected solutions are shown in fig. 4, the culture solutions here 
used being represented by dots. It will be seen that solutions 
from all of the triangles are included. The method of desig- 
nation is the same as in series 1, but fractional numbers must 
be used to designate solutions which do not fall upon the points 
of intersection of the lines. In solution T2R43C12, for exam- 
ple, the four salts contribute the following portions of the total 
osmotic concentration: Potassium chloride, 0.2; monopotassium 
phosphate, 0.43; calcium nitrate, 0.1%; and magnesium sulphate, 
0.1%. For comparison, Shive’s best three-salt solution for wheat 
and Tottingham’s best four-salt solution were again used. 
