238 DIONÆA MUSCIPULA. (Cap. XIII. 
analogy of Drosera, the heat in these several cases was too 
great and too suddenly applied. The surface of the blade is 
very slightly sensitive; it may be freely and roughly handled, 
without any movement being caused. A leaf was scratched 
rather hard with a needle, but did not close; but when the 
triangular space between the three filaments on another leaf 
was similarly scratched, the lobes closed. They always 
closed when the blade or midrib was deeply pricked or cut. 
Inorganic bodies, even of large size, such as bits of stone, 
glass, &c.—or organic bodies not containing soluble nitro- 
genous matter, such as bits of wood, cork, moss, or bodies 
containing soluble nitrogenous matter, if perfectly dry, such 
as bits of meat, albumen, gelatine, &c., may be long left (and 
many were tried) on the lobes, and no movement is excited. 
The result, however, is widely different, as we shall presently 
see, if nitrogenous organic bodies which are at all damp, are 
left on the lobes; for these then close by a slow and gradual 
movement, very different from that caused by touching one 
of the sensitive filaments. The footstalk is not in the least 
sensitive; a pin may be driven through it, or it may be cut 
off, and no movement follows. 
‘The upper surface of the lobes, as already stated, is 
thickly covered with small purplish, almost sessile glands.* 
These have the power both of secretion and absorption ; but, 
unlike those of Drosera, they do not secrete until excited 
by the absorption of nitrogenous matter. No other excite- 
ment, as far as I have seen, produces this effect. Objects, 
such as bits of wood, cork, moss, paper, stone, or glass, may 
be left for a length of time on the surface of a leaf, and it 
remains quite dry. Nor does it make any difference if the 
lobes close over such objects. For instance, some little balls 
of blotting-paper were placed on a leaf, and a filament was 
touched; and when after 24 hrs. the lobes began to re-open, 
* [Gardiner has described these protoplasm is much less granular 
glands in the ‘ Proceedings of the R. 
Society,’ vol xxxvi. p.180. When at 
rest the gland-cells show a granular 
protoplasm, containing in most cases 
a single large vacuole; the nucleus is 
situated at the base of the cell. At 
the end of the secreting period the 
following changes have occurred, The 
nucleus seems to diminish in size, it 
has assumed a central position; the 
than before, and contains a number 
of small vacuoles, so that the nucleus 
appears suspended by radiating 
strands of protoplasm in the centre 
of the cell. 
Another change produced by the 
feeding the leaf is the appearance, in 
the parenchyma, of tufts of greenish 
yellow crystals of unknown nature.— 
F, D] 
