56 FREAKS OF PLANT LIFE. 



margin, with minute reddish or purplish glands, but 

 there are no glands on the leaf-like foot-stalk. The 

 glands are elevated on short pedicels, and are convex 

 above. Little stellate projections of an orange- 

 brown colour, with eight radiating arms, are scattered 

 over the foot-stalk, the back of the leaves, and the' 

 basal part of the marginal spikes, and a very few on 

 the surface of the lobes. Here and there a few 

 minute pointed hairs may be traced on the back of 

 the leaves. 



The functions of all these parts have been fairly 

 ascertained. That of the marginal spines is of a 

 mechanical nature, and perhaps entirely so, as they 

 are neither sensitive nor glandular, and do not seem 

 to possess any separate or spontaneous motion. The 

 sensitive filaments, on the contrary, are eminently 

 sensitive. Their apices are sometimes divided into 

 two or three points, and, from apex to base, it is 

 impossible to touch them, ever so lightly, without at 

 once acting on the lobes of the leaf and causing them 

 to close. These sentinel filaments, although so sensi- 

 tive to a slight touch, are less sensitive to prolonged 

 pressure. This difference between the filaments in 

 Dioncea and the glands of Drosera relates to the 

 different habits of the two plants. It has been seen 

 how a slight prolonged pressure acts on the Sundew ; 

 but in the Dioncea there is no viscid secretion to 

 detain the insect, which must be caught at once by 



