Potassium to Growth in Plants. 
21 5 
by just so much the normal life cycle. We found, it will be remembered, 
the plants of wheat at different stages of maturity when Experiment 2 
was concluded. The complete life cycle would not have occurred in the 
potassium-starved plants, but would have reached completion in those plants 
that were supplied with the element. 
Experiment 3. Early pedigree Dent field Corn was grown in water 
culture in this experiment, solution F being used. The plants were grown 
in the full nutritive solution, in the nutritive solution less potassium, and in 
the nutritive solution to which potassium was only added after three, six, 
nine, and twelve days, four jars containing three plants being used in each 
case. The experiment was begun on April 5, the seedlings placed in the 
Table XXV. Effect of delayed additions of potassium on the amount of 
potassium in Blue stem Wheat plants grown in sand culture. 
Method of treatment. 
No. of 
plants. 
Total 
amount of 
potassium. 
Amount of 
potassium 
in o n e 
plant. 
Total 
potassium 
utilized 
per gramme 
of dry 
matter 
Potassium 
absorbed 
from the 
pabulum 
by one 
formed. 
plant. 
Mg. 
Mg. 
Mg. 
Mg. 
Potassium present 
from 
6 
264.3 
44.05 
82.48 
39*94 
the beginning. 
Potassium added 
after 
7 
285.6 
40.8 
72-00 
40-69 
3 days. 
Potassium added 
after 
7 
304-5 
43-5 
68.07 
43-39 
6 days. 
Potassium added 
after 
8 
342.0 
42.7 
70.76 
42.59 
9 days. 
Potassium added 
after 
7 
3i5-o 
45.0 
78.02 
44.89 
12 days. 
Potassium added 
17 days. 
Potassium added 
after 
10 
261-1 
26-11 
72.01 
26.00 
after 
10 
162.1 
16.20 
64.82 
16.90 
22 days. 
Potassium absent 
10 
4-5 
0.45 
9-45 
o-34 
jars then having roots about 0-5 cm. long, but the epicotyl was still enclosed 
in the coleoptilum. At the end of thirty-two days the experiment was 
brought to a close, as the plants growing in the absence of potassium had 
not only ceased growing but had practically dried up, exhibiting all the 
symptoms of potassium starvation. The plants growing in the full nutritive 
solution, as well as those which had received potassium after three and six 
days, were, on the other hand, all healthy and growing normally. The 
plants deprived of potassium for nine days showed symptoms of starvation, 
but were growing. The plants deprived of potassium for twelve days, while 
still growing, had their lowest leaves completely withered, and the others 
with tips and edges partly dried. The general effect produced on dry 
weight and on the ratios of top weight to root weight of the plants in the 
