Dec., 1908.] 
The Effect of Alkaloids. 
407 
tions of atropine and strychnine, such as w^re obtained by 
means of filtrating these solutions through lamp black or through 
calcium carbonate (1), the process of regeneration was aug¬ 
mented to a remarkable degree. Solutions of strychnine (Fig. 
4) act differently upon different plants, but the greatest stimu¬ 
lation is caused invariably by the weaker solutions. Stronger 
solutions, though they may stimulate growth at first, soon 
become injurious to the plant. 
At the end of twelve days after the operation the differences 
in size of the regenerating plants became much more pronounced 
than those seen in the figures shown here. 
In the following table are given the data concerning the 
green and dry weight of the plants. 
Table II. 
Solution 
' 0.01% 
0.001% 
0.0001% 
Weight of pits. 
Weight of pits. 
Weight of pits. 
in grs. 
in grs. 
in 
grs. 
Green 
Dry 
Green 
Dry 
Green 
Dry 
Strychnine 
2.25 
0.56 
3.50 
0.88 
5.00 
1.25 
Digitalin 
3.75 
0.94 
4.80 
1.20 
7.70 
1.93 
Pilocarpine 
6.65 
1.64 
5.05 
1.26 
5.95 
1.49 
Atropine 
2.95 
0.74 
2.25 
0.56 
3.25 
0.S1 
Control I 
2.40 
0.60 
Control II 
1.85 
0.46 
It may be seen from this table that the inference which should 
be drawn from records of the weight of the regenerated stems 
practically coincides with data obtained from the study of their 
transpiration and actual size. 
On the 15th of March, i. e., seventeen days after the operation 
the regenerated stems were cut off once more with sharp scissors 
near their proximal ends. The object in performing this experi¬ 
ment was to find out how the plants would behave in regeneration 
after a second operation. In a previous work on regeneration in 
the fresh water oligochaete, Lumbriculus, (oa) it was pointed out 
that the rate of regeneration in that animal decreases after suc¬ 
cessive operations, so that if we designate the rate of regeneration 
after the first operation by a unit, the rate of regeneration after a 
second operation would be only one-half of a unit, and one-fourth 
of a unit after the third operation, the length of time during 
which the animals are allowed to regenerate being, of course, the 
same in all three cases. Zeleny (8), on the other hand, finds that 
