232 DIONZA MUSCIPULA. (Cuar. XII. 
remarkable from their extreme sensitiveness to a touch, as 
shown not by their own movement, but by that of the lobes. 
The margins of the leaf are prolonged into sharp rigid pro- 
jections which I will call spikes, into each of which a bundle 
of spiral vessels enters. The spikes stand in such a position 
that, when the lobes close, they interlock like the teeth 
of arat-trap. The midrib of the leaf, on the lower side, is 
strongly developed and prominent. 
The upper surface* of the leafis thiekly covered, excepting 
towards the margins, with minute glands of a reddish or 
Fig. 12. 
(Dionea muscipula.) 
Leaf viewed laterally in its expanded state. 
purplish colour, the rest of the leaf being green. There are 
no glands on the spikes, or on the foliaceous footstalk. The 
glands are formed of from twenty to thirty polygonal cells, 
filled with purple fluid. Their upper surface is convex. 
They stand on very short pedicels, into which spiral vessels 
do not enter, in which respect they differ from the tentacles 
of Drosera. They secrete, but only when excited by the 
absorption of certain matters; and they have the power of 
* (A. Fraustadt, in his Breslaudis- fact. It is easy to see that the lower 
sertation on Dionza (Mar. 1876) states 
that the upper surface of the leaf 
is devoid of stomata. C. De Candolle, 
‘Archives des Sciences Phys. et Nat.’ 
Geneva, April 1876, mentions the same 
surface of the leaf 1s a better one for 
the development of stomata than the 
upper surface, which is liable to be 
constantly bathed in secretion.— 
F. D.] 
