210 DROSERA ROTUNDIFOLIA. Cuap. LX, 
wished, therefore, to ascertain whether camphor would render the 
leaves of Drosera more sensitive to mechanical irritation than 
they naturally are. Six leaves were left in distilled water for 
5 m. or 6m., and then gently brushed twice or thrice, whilst still 
under water, with a soft camel-hair brush; but no movement 
ensued. Nine leaves, which had been immersed in the above 
solution of camphor for the times stated in the following 
table, were next brushed only once with the same brush and in 
the same manner as before; the results are given in the table. 
My first trials were made by brushing the leaves whilst still 
immersed in the solution ; but it occurred to me that the viscid 
secretion round the glands would thus be removed, and the 
camphor might act more effectually on them. In all the 
following trials, therefore, each leaf was taken out of the solu- 
tion, waved for about 15 s. in water, then placed in fresh water 
and brushed, so that the brushing would not allow the freer 
access of the camphor ; but this treatment made no difference 
in the results. 
a peengeh of 
4 ‘ime between 
3 Length of the immersion 
1 [Immersion in Length of ‘Time between the Act of Brushing | the Leaves in 
2 the Solution i : ne Polition 
5 : and the Inflection of the Tentacles, and the First 
2 | of Camphor. Sign of the 
= Inflection of the 
zi Tentacl:s. 
115 3m. considerable inflection ; 4 m. all)' 8 
mes the tentacles except 3 or 4 inflected. ADs 
2 |5m. 6 m. first sign of inflection. 11 m. 
j 6m, 80s. sli¢ht inflection ; 7 m. 30s. 
5 | Sim { plain inflection. Hm, ie 
2m. 30s. a trace of inflection; 3 m. 
4 |4m.50s. { plain; 4 m. strongly marked. } ome 
4 2 m. 30 s. a trace of inflection; 3m. 6 m.30 
2 ™m plain inflection. } De 
6 | 4 2m. 30s. decided inflection; 31n. 30s. 6 m.30 
mM strongly marked. ae: 
2m. 30 8. slight inflection ; 
7 [4m { plain; 4m. well marked. ii, Gi.a0)s, 
813 2m. trace of inflection; 3 m. con- ati 
i siderable, 6 m. strong ‘inflection. i 
9 13 f2 m. trace of inflection ; 3 m. con- 5m 
ve { siderable, 6 m. strong inflection. t . 
Other leaves were Icft in the solution without being brushed ; 
one of these first showed a trace of inflection after 11 m.; a 
second after 12 m.; five were not inflected until 15 m. had 
