54« 
Journal of Agricultural Research 
Vol. XXI, No. 8 
consist of a complete solution and one lacking in two elements. Data 
on the growth of plants in these three pairs of solutions are given in 
Table II, and data on the assimilation of nitrogen, phosphoric acid, and 
potash in Table III. 
The plants having half their roots in incomplete solutions had slightly 
higher ratios of roots to tops than the control plants, which had all their 
roots in the complete solution. 1 It is also noticeable that plants 33 to 80 
showed a greater growth of roots in the A flasks, which contained the com¬ 
plete solution, than in the B flasks containing the incomplete solutions. 
The means of the amounts of nitrogen, phosphoric acid, and potash 
assimilated by plants 33 to 48, 49 to 64, and 65 to 80 were almost identical. 
The relative amounts of nitrogen, phosphoric acid, and potash assimilated 
by these three sets of plants varied, however, according to the character 
of the incomplete solution in flask B. 
Experiment II.— The roots divided between a complete solution and a 
solution lacking three elements. 
The data on growth and on the assimilation of nitrogen, phosphoric 
acid, and potash, along with the results of experiment VIII, are given in 
Tables XIV and XV. 
While plants 49 to 64 had almost the same numbers of roots in the A 
and B flasks, nearly two-thirds of the total root growth was in the A flask 
containing the complete solution. The roots in the complete solution 
were much shorter and more bushy than those in the solution lacking 
nitrogen, phosphorus, and potassium. 
The proportions in which nitrogen, phosphorus, and potassium were 
assimilated by plants 49 to 64 differed but little from the proportions 
assimilated by the control plants, 1 to 16, although the mean assimila¬ 
tion of these three elements by plants 49 to 64 was only about two-thirds 
that of the controls. It would be interesting to know whether assimila¬ 
tion would be cut to 50 per cent if one-half the roots were maintained 
in water containing no nutrients whatever—that is, no sodium, calcium, 
magnesium, iron, chlorids, and sulphates. Because of the difficulty of 
preparing sufficient quantities of suitable distilled water, this was not 
determined. 
Experiment III. — The roots divided between two solutions, each of 
which lacked one element. 
The three nutrient solutions lacking in nitrogen, phosphorus, and 
potassium, respectively, may be combined in three pairs. The growth 
made in these three pairs of solutions, and the analyses of the plants are 
shown in Tables IV and V. It will be noted that the growths made by 
the plants in each of the three pairs of incomplete solutions varied 
markedly. Roughly, the root to top ratios were inversely proportional 
to the growths of tops. 
1 The root to top ratio is taken as the weight of dry roots divided by the weight of dry leaves and stalks 
(tops). 
