CHAP. XIII. STRUCTUEE OF THE LEAVES. 287 



The two lobes stand at rather less than a right angle 

 to each other. Three minute pointed processes or 

 filaments, placed triangularly, project from the upper 

 surfaces of both ; but I have seen two leaves with four 

 filaments on each side, and another with only two. 

 These filaments are 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 projections 

 which I will call spikes, into each of which a bundle 



Fir,. 12. 



(IHonaa musciputn.^ 

 Leaf viewed laterally in its expands,' state. 



of spiral vessels enters. The spikes stand in such 

 a position that, when the lobes close, they inter-lock 

 like the teeth of a rat-trap. The midrib of the 

 leaf, on the lower side, is strongly developed and 

 prominent. 



The upper surface of the leaf is thickly covered, 

 excepting towards the margins, with minute glands of 

 a reddish or 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 



