Cuar. XVL MOVEMENTS OF THE LEAVES. 377 
there was a trace of movement in 1 hr. or J hr. 30 m. 
The pressure from fragments of glass excites move- 
ment almost as quickly as the absorption of nitro- 
genous matter, but the degree of incurvation thus 
caused is much less. After a leaf has become well 
incurved and has again expanded, it will not soon 
answer to a fresh stimulus. The margin was affected 
longitudinally, upwards or downwards, for a distance of 
‘13 of an inch (3:302 mm.) from an excited point, but 
for a distance of ‘46 of an inch between two excited 
points, and transversely for a distance of ‘2 of an 
inch (5°08 mm.). The motor impulse is not accom- 
panied, as in the case of Drosera, by any influence 
causing increased secretion; for when a single gland 
was strongly stimulated and secreted copiously, the 
surrounding glands were not in the least affected. 
The incurvation of the margin is independent of in- 
creased secretion, for fragments of glass cause little 
or no secretion, and yet excite movement; whereas 
a strong solution of carbonate of ammonia quickly 
excites copious secretion, but no movement. 
One of the most curious facts with respect to the 
movement of the leaves is the short time during which 
they remain incurved, although the exciting object is 
left on them. In the majority of cases there was well- 
marked re-expansion within 24 hrs. from the time 
when even large pieces of meat, &c., were placed on 
the leaves, and in all cases within 48 hrs. In one 
instance the margin of a leaf remained for 32 hrs. 
closely inflected round thin fibres of meat; in another 
instance, when a bit of sponge, soaked in a. strong in- 
fusion of raw meat, had been applied to a leaf, the 
margin began to unfold in 35 brs. Fragments of glass 
keep the margin incurved for a shorter time than do 
nitrogenous bodies; for in the former case there was 
