192 BOTANICAL GAZETTE [SEPTEMBER 
Transpiration both per unit area and per gram of tops increases quite 
markedly with the increasing fertility of the extract. 
Series XII.—This consists of duplicates of cultures 1, 2, 4, and 
6 of Series XI. The cultures were carried on at the same time as 
were those of the former series. One bottle, containing four plants, 
2, was used for each culture. Leaf 
area was not determined. The curves 
are given in jig. 17. 
From them it is seen that the 
2 
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5 th mi appear here, and the discrepancy 
culture 2 also disappears. 18 
relatively high transpiration of the 
garden soil is again exhibited ig 
<3. by both weg and transpiration 
pe 27 the cultures fall in the same ordth 
and this is the order 
obtained in the pre- 
ceding series. Regard- 
ing the relation of 
Takoma soil to Cecil 
clay poor, it may be 
that the deleterious 
properties of the former 
are more pronounced 
in aqueous extract 
than in the soil itself. 
Series XIII.—This 
consists of five differ- 
ent nutrient solutions. 
No. 1 is a solution of 
the necessary salts 8 
which had already had —- 
crag is the 
wheat plants growing in it for twenty days. No. : put witht? 
one part per million pyrogallol added. No. 3 is the sam 
