184 DROSERA ROTUNDIFOLIA. [Cuar. IX. 
others, again, such as the acetate of quinine and digitaline, 
caused strong inflection. 
The several substances mentioned in this chapter affect the 
colour of the glands very differently. These often become dark 
at first, and then very pale or white, as was conspicuously 
the case with glands subjected to the poison of the cobra 
and citrate of strychnine. In other cases they are from the 
first rendered white, as with leaves placed in hot water and 
several acids; and this, I presume, is the result of the coagu- 
lation of the albumen. On the same leaf some glands become 
white and others dark-coloured, as occurred with leaves in a 
solution of the sulphate of quinine, and in the vapour of 
alcohol. Prolonged immersion in nicotine, curare, and even 
water, blackens the glands; and this, I believe, is due to the 
aggregation of the protoplasm within their cells. Yet curare 
caused very little aggregation in the cells of the tentacles, 
whereas nicotine and sulphate of quinine induced strongly 
marked aggregation down their bases. The aggregated 
masses in leaves which had been immersed for 3 hrs. 15 m. 
in a saturated solution of sulphate of quinine exhibited inces- 
sant changes of form, but after 24 hrs. were motionless; the 
leaf being flaccid and apparently dead. On the other hand, 
with leaves subjected for 48 hrs. to a strong solution of the 
poison of the cobra, the protoplasmic masses were unusually 
active, whilst with the higher animals the vibratile cilia and 
white corpuscles of the blood seem to be quickly paralysed 
by this substance. 
With the salts of alkalies and earths, the nature of the base, 
and not that of the acid, determines their physiological action 
on Drosera, as is likewise the case with animals; but this 
rule hardly applies to the salts of quinine and strychnine, for 
the acetate of quinine causes much more inflection than the 
sulphate, and both are poisonous, whereas the nitrate of 
quinine is not poisonous, and induces inflection at a much 
slower rate than the acetate. The action of the citrate of 
strychnine is also somewhat different from that of the 
sulphate. 
Leaves which have been immersed for 24 hrs. in water, 
and for only 20 m. in diluted alcohol, or in a weak solution 
of sugar, are afterwards acted on very slowly, or not at all, 
by the phosphate of ammonia, though they are quickly acted 
on by the carbonate. Immersion for 20 m. in a solution of 
gum arabic has no such inhibitory power. The solutions of 
mg ne =y 
