Turgor and of Temperature on Growth . 379 
Owing to its greater sensitiveness, a series of radicles of 
Lupinus albus gave a decided reaction after one hour in 
a 1 per cent, solution. 
In Table VII are shown the details. The averages are 
drawn from 4 specimens. 
During the hour spent in the KN0 3 solution, the operative 
factors give as a resultant no measurable change of length. 
The mechanical contraction due to the turgor-change is 
approximately balanced by the slight growth following. The 
return to water is seen to be followed by a decided reaction. 
It seems hardly probable that here we have, indeed, the 
simple result of the change from KNO s to water. In view 
TABLE VIII. 
Period. 
Growth. 
Medium. 
II-II.30 
18 units of scale 
Water 
II. 30-1 2 
10 
99 99 
99 
12-2.30 
*16 
99 99 
99 ' 
2.'30-3 
26 
99 n 
99 
3-3-30 
18 
99 9 9 
99 
3-30-4 
22 
9) 99 
» 
4-4.3O 
25 
99 99 
99 
4.30-5 
21 
99 9 9 
» 
5-5.30 
24 
99 9 9 
"9 
5-30-6 
25 
9 9 9 9 
9 9 
6-6.30 
28 
9 9 99 
99 
6.30-7 
26 
9 9 99 
»• 
* Rate of growth per half-hour, i unit of scale = 0*0169 mm. 
of the short time elapsing after the transfer to the KN0 3 
solution, it is likely that before recovery from this shock has 
taken place, the second change of substratum occurs, and the 
retardation observed is probably the reaction to both stimuli. 
An analysis into the components was not attempted. 
It appears, as would be expected, that the stimulus can be 
so reduced that no measurable reaction can be detected by 
measurements made with the scale. 
