1910] SCHREINER & SKINNER—ABSORPTION AND GROWTH 5 
therefore, that any point within the triangle represents a mixture 
composed of the three constituents, its position in the triangle being 
determined by the composition of the mixture, namely the ratio of the 
three component parts, P,O,, NH,, and K,O. For instance, point 
12, being on the 60 per cent phosphate line, represents this composition 
of P,O,, namely 60 per cent, and being at the same time on the 10 per 
cent NH, line, and the 30 per cent K,O line, it represents 10 per cent 
and 30 per cent of these constituents, respectively. The composition 
of the mixture represented by this point is, therefore, P,O,; 60 per 
cent, NH, 10 per cent, K,O 30 per cent; i.e., the ratio of these con- 
stituents in the fertilizer mixture is 60-10-30 or 6-1-3. Similarly, 
the point 34 represents the following mixture of the composition: 
P,O, 30 per cent, NH, 50 per cent, KO 20 per cent, or a fertilizer 
ratio of 3-5-2. 
For the sake of convenience in stating such ratios or percentage 
composition of the fertilizer mixtures in this investigation, the figures 
are always given in the order P,O,, NH,, and K,O, as shown above. 
The triangle, therefore, represents single fertilizer constituents 
at the apices or vertices, mixtures of any two constituents along the 
boundary lines of the triangle, and mixtures of all three constituents 
within the triangle. 
Solution culture methods 
Before proceeding with a description of the general appearance 
of the cultures growing in solutions with the different fertilizer ratios, 
it may be well to describe briefly here the solution-culture method 
used in these experiments, as the manner of procuring a sufficiently 
large number of seedlings and of preparing physiologically pure water 
are important factors in carrying on this or allied investigations. 
METHOD OF PROCURING UNIFORM SEEDLINGS 
In the work under consideration, as well as in other work in prog- 
ress in these laboratories, it is necessary to have a large number, often 
several hundred and sometimes thousands, of uniform seedlings; 
ie., seedlings of the same age and equal in development and general 
vitality. The general principle on which this equal germination of 
