114 
Research Bulletin No. 3 
The first sign of injury was observed early in August in the 
case of I, and on August 11 the tips of all branches on the plants 
in this were dead and the lowest leaves had begun falling. In II 
and III, on the same date, the tips were uninjured and no leaves 
had fallen. Growth had ceased in I and II by August 15, when 
the photograph (figure 37) was taken, and in III by September 1. 
On August 16 the tallest plant in I was in the worst condi- 
tion, while many leaves had fallen from the second plant and a 
few from the third. In II all the tips were dead and the lowest 
leaves had fallen. In III none of the plants was yet injured. 
Cylinder I was opened on September 23 and the other two 
were opened on October 13. In none were all the plants dead 
when the cylinders were opened but in the case of each all the tips 
had died and nearly all the leaves had fallen; the most vigorous 
plant in each retained only from five to seven compound leaves. 
The cylinders were weighed on June IT, after the plants had 
been placed in them, and again on August 17 after the first signs 
of injur} 7 from drouth were noticed. After the latter date they 
were weighed at intervals until opened, using scales sensitive to 
15 grams. During the three weeks preceding the opening of cylin- 
ders II and III the loss in weight was practically nothing, while 
during one week, September 23 to 30, there was a slight gain in 
weight. This week was characterized by cloudiness and un- 
usually high humidity of the air, and the increase in weight is to 
be attributed to the increase in the amount of hygroscopic mois- 
ture in the dry surface mulch. Table 31 shows the loss in weight 
of the cylinders and the average per cent of water in the soil of 
the different cylinders. The weights of the plants are included in 
those of the soil, but the former were too small to appreciably 
affect the results. 
In none of the cylinders did a crevice form between cylinder 
wall and soil column. The roots penetrated to the bottom of the 
cylinders, being most abundant in the lowest three-inch section. 
The moisture conditions existing at the time of opening the cylin- 
ders are shown in Table 32. Free water had entirely disappeared. 
Below the first foot the moisture content was practically uni- 
form. The black surface soil, in which the plants had been started 
and which was transferred with these, appears, from the mere 
statement of the amount of free water, to be drier than the con- 
tiguous subsoil, but in reality it is not, both being about half 
saturated with hygroscopic moisture. This black soil was pres- 
ent in the form of three or four conical masses surrounded en- 
tirely by H O subsoil. 
Summary op experiments. — The plants remained alive after 
the water content had fallen slightly, but distinctly, below the 
