21)0 DION^EA MUSCIPULA. CHAP. XIIL 



the glands of Diosera evidently stands in relation to 

 the habits of the two plants. If a minute insect alights 

 with its delicate feet on the glands of Drosera, it is 

 caught by the viscid secretion, and the slight, though 

 prolonged pressure, gives notice of the presence of 

 prey, which is secured by the slow bending of the 

 tentacles. On the other hand, the sensitive filaments 

 of Diomea are not viscid, and the capture of insects 

 can be assured only by their sensitiveness to a 

 momentary touch, followed by the rapid closure of 

 the lobes. 



As just stated, the filaments are not glandular, and 

 do not secrete. Nor have they the power of absorption, 

 as may be inferred from drops of a solution of car- 

 bonate of ammonia (one part to 146 of water), placed 

 on two filaments, not producing any effect on the 

 contents of their cells, nor causing the lobes to close. 

 When, however, a small portion of a leaf with an 

 attached filament was cut off and immersed in the same 

 solution, the fluid within the basal cells became almost 

 instantly aggregated into purplish or colourless, irre- 

 gularly shaped masses of matter. The process of 

 aggregation gradually travelled up the filaments from 

 cell to cell to their extremities, that is in a reverse 

 course to what occurs in the tentacles of Drosera when 

 their glands have been excited. Several other fila- 

 ments were cut off close to their bases, and left for 1 hr. 

 30 m. in a weaker solution of one part of the carbonate 

 to 218 of water, and this caused aggregation in all 

 the cells, commencing as before at the bases of the 

 filaments. 



Long 1 immersion of the filaments in distilled water 



o 



likewise causes aggregation. Nor is it rare to find 

 the contents of a few of the terminal cells in a 

 spontaneously aggregated condition. The aggregated 



