1918} BAKKE—WILTING IOI 
which is present between the leaves it would be expected that the 
‘ variation would not be as great. 
The data given in table VI show slowly decreasing values; 
however, the decrease is not marked. The highest foliar transpir- 
ing power for Ib, is 0.35, while the lowest is 0.10. The highest 
point as here set forth occurs on the 21st hour on July 26, while 
on the following day the index at the same time is 0.34. After 
that there is a slight fall, although this is not true for all the 
readings, for on July 30 the index iso.31. Even at the time of 
wilting, the index at the morning hour is 0.26. From July 29 
to July 31 the maximum values are approximately the same. 
This is also true of the minimum values. The last reading for the 
Ib, series occurs on July 31 and gives an index of 0.13. 
For leaf Id, the values are strikingly similar to those of the 
leaf situated just below it upon the stem. The highest transpir- 
ing power index for the entire time is only 0.28, and occurs at 9: 35, 
July 26; while the minimum value 0.10 occurs on the 14th hour 
of July 29 and on the 2rst hour of July 31. The data of table VI, 
tepresented graphically in fig. 5, show a gradual dropping off of 
the day maximum values from July 26 to July 30. From July 30 
to August 3, with the exception of August 1, the graph of wilting is 
practically a straight line. On August 3 there is a marked increase, 
considering that the entire period has given a low index throughout 
from 0.15 to 0.20, or an increase of 33.3 per cent). Usually 
during the march of foliar transpiring power a drop is registered 
at the 14th or 15th hour. On July 27 there is an increase of the 
index from 0.13 to 0.18 (38.46 per cent) and on July 31 from 0.14 
to 0.17 (21.43 per cent). On account of the comparatively small 
deviation between the maximum and minimum values throughout, 
the increase in the transpiring power of one-third on August 3 
becomes more significant than the graph shows (fig. 5). 
The ratio between the day indices and night indices is presented 
as before, the readings of the gth and 21st hours being used. On 
July 24 the morning reading is 0.17; on the following days the 
average foliar indices of transpiring power for leaf Ib, areo.12,0.12, 
©.10, 0.22, 0.25, 0.31, 0.26. The corresponding night values are 
0.18, 0.19, 0.35, 0.34, 0.12, 0.14,0.26,0.13. The corresponding 
