8 DROSERA ROTUNDIFOLIA. Chap. I. 



the cells of tlie pedicels are rendered of a bright red, with the 

 exception of those close beneath the glands. These latter cells 

 lose their pale red tint ; and the green matter which they, as 

 well as the basal cells, contain, becomes of a brighter green. 

 The petioles bear many multicellular hairs, some of which 

 near the blade are surmounted, according to Nitschke, by a 

 few rounded cells, which appear to be rudimentary glands. 

 IJoth surfaces of the leaf, the pedicels of the tentacles, espe- 

 cially the lower sides of the outer ones, and the petioles, are 

 studded with minute papillie (hairs or trichomes), having a 

 conical basis, and bearing on their summits two, and occasion- 

 ally three or even four, rounded cells, containing much proto- 

 ])lasm. These papilla} are generally colourless, but sometimes 

 include a little purple fluid. They vary in development, and 

 graduate, as Kitschke * states, and as I repeatedly observed 

 into the long multicellular hairs. The latter, as well as the 

 l>a]Mllaj, are probably rudiments of formerly existing tentacles. 



I may here add, in order not to recur to the papillss, that they 

 do not secrete, but are easily permeated by various fluids : thus 

 when living or dead leaves are immersed in a solution of one 

 part of chloride of gold, or of nitrate of silver, to 437 of water, 

 they are quickly blackened, and the discoloration soon spreads 

 to the surrounding tissue. The long multicellular hairs are 

 not so quickly afi"ected. After a leaf had been left in a weak 

 infusion of raw meat for 10 hours, the cells of the papillae had 

 evidently absorbed animal matter, for instead of limpid fluid 

 tlu-y now contained small aggregated masses of protoplasm, 

 which slowly and incessantly changed their forms. A similar 

 result followed from an immersion of only 15 minutes in a 

 sohition of one part of carbonate of ammonia to 218 of water, 

 and the adjoining cells of the tentacles, on which the papillas 

 were seated, now likewise contained aggregated masses of proto- 

 plasm. We may therefore conclude that when a leaf has closely 

 clasped a captured insect in the manner immediately to be 

 described, the papilla), which project from the upper surface 

 of the leaf and of the tentacles, probably absorb some of the 

 animal matter dissolved in the secretion ; but this cannot be 

 the case with the papilla) on the backs of the leaves or on the 

 petioles. 



* Nitsclikc has elaborately described and figured these papilla), 

 *13ot. Zeitun-,' ISGI, pp. 2;]4, 25:^, 251. 



