14 BOTANICAL GAZETTE [JULY 
this region of greatest growth, therefore, that the greater absorption 
took place with the least change in ratio; in other words, the solutions 
represented by this region offered the best environment for plant 
development and the best ratios for the absorption of plant nutrients. 
Attention might also be called to the fact that in the ratios where 
the nitrate was low, there has been a movement to the no nitrate line, 
or at least so close to this line that it was impossible to plot them other- 
wise. After the comparatively small amount of nitrate was removed 
or reduced to a minimum, the point marking the ratio would have 
to move along the no nitrate base line in the direction either of the 
potash or of the phosphate, depending upon which was removed in 
the larger amount. The diagram shows that this movement of the 
ratio in the solutions was in nearly all cases toward the phosphate 
apex of the triangle. It is obvious that such a condition of affairs 
will cause a shifting of the lines connecting the ratios in the diagram, 
and that a similar state of affairs in the cultures on the low potassium 
line would produce a shifting of the ratio lines in the opposite direction. 
An examination of the diagram shows this has occurred, because the 
ratio lines in the upper part of the triangle show a divergence, giving 
a fanlike effect. Inthecase of the potash this divergence is also 
strongly noticeable, although the potash was never so completely 
removed as was the case with the nitrate. 
The results of the experiments considered by periods 
The very earliest periods, when compared with the later periods, show | 
’ some differences in the ratio in which the three elements are removed, 
as has already been pointed out. Mention has been made of the fact 
that the ratios removed from the solutions along the lower phosphate 
line, namely, the 8 parts per million line of cultures, had a tendency 
to cause the ratio lines to turn from a point below this line to points 
above the line with increase in time. This general behavior of the 
cultures is very well shown by the three diagrams for the first, second, 
and third periods. The first diagram (fig. 6) shows the arrow points 
of the 10 per cent phosphate mixtures to lie below this line. The 
second diagram (fig. 7) shows some of the points above and some 
still below the line. In the third diagram (fig. 8) all but one arrow 
point lie above the line, and some arrow points of the 20 per cent 
