406 
The Ohio Naturalist. 
[Vol. IX, No. 2, 
Table I. 
Date — February 27, to March 15, 1908. 
Solution 
Transpiration 
Total 
Daily Average 
Control I 
Control II 
69.95 grms. 
58.65 “ 
4.12 grms. 
3.45 
Strychnine 0.01% 
“ 0.001% 
“ 0.0001% 
43.95 grms. 
93.10 
91.20 
2.59 grms. 
5.48 
5.37 “ 
Digitalin 0.01% 
“ 0.001% 
“ 0.0001% 
64.60 grms. 
90.65 
123.30 
3.80 grms. 
5.33 
7.25 
Pilocarpine 0.01% 
0.001% 
“ 0.0001% 
108.90 grms. 
61.05 “ 
108.55 “ 
6.46 grms. 
3.59 
6.39 
Atropine 0.01% 
0.001% 
0.0001% 
65.25 grms. 
61.90 
80.35 
3.84 grms. 
3.64 
4.73 
The illustrations (Figs. 1-4) which are reproduced from 
photographs of plants that had been regenerating about 8 days 
after the epicotyls were cut off, will serve for comparing the 
actual sizes attained by the different plants. Reading from left 
to right the arrangement of the cultures in the photographs is 
in all cases as follows: control, solutions a,b,c. From these figures 
it will be seen that the rate of regeneration varies both with the 
nature of the medium and also with the strength of the solution 
in which the plants regenerated. In pilocarpine (Fig. 1) the 
plants developed more luxuriantly than the controls and the 
greatest acceleration is shown in both the stronger and the 
weaker solution (0.01% and 0.001%). In solutions of digitalin 
(Fig. 2) the greatest acceleration took place in the weaker solu¬ 
tion, while the regeneration was slower in the strong solution 
(0.01%,). Atropine (Fig. 3) and strychnine act as stimuli only in 
very weak solutions (0.0001%). In extremely attenuated solu- 
