vStuijiks of Hkalth in Potatofs. 
t9 
Tlie more we have of one condition, the less we can have of t^^e 
• others if we are to make a good crop. 
When the higher percentages of moisture were used, the 
leaves and stems collapsed very quickly, within less than a day, in 
the 8o° cabinet, somewhat less quickly in the 65° cabinet, and not 
at all in the 50° cabinet. It is to be supposed that the roots were 
in better condition in the cooler cabinets and were less easily 
drowned. The effect of the high temperature and soakage was, 
evidently, the crippling of roots by heat and the exclusion of air, so 
that the roots could not supply the tops, which then wilted for lack 
of water. 
After 90 days the stems were cut just beneath the soil and 
were submitted for examination to Professor Walter G. Sackett, 
of the Colorado Experiment Station. He found a species of 
Fusarium present in some of the stems and absent in others, accord¬ 
ing to a very definite rule. As the examinations were being made 
we were able to foretell in advance whether or not the Fusarium 
would be found. The results were absolutely uniform. There 
were no exceptions. 
We regard the presence or absence of the fungus in these 
experiments as a secondary matter; as an index of the health, or 
lack of health, of the plants under the conditions to which they 
Figure 11.—From left to right: 1. Moisture at 10 per cent (8-12) negative. 
2. Twice flooded. “Rizoc” and Fusarium. 3. Started at 10, once flooded by 
accident. “Rizoc” and Fusarium. 4 Moisture at 20 per cent. Check, the same. 
Both negative. Note the abundamt health of the plant on the right, though 
grown from leaf-roll seed in leaf-roll soil. 
