'368 TttR OAXAOIAN NA'n liALlHT. [Vol. vii. 



Darwii! ill Droser;!, to briim; iilxnit rcmaikaijle clianges in their 

 protoplasm, ending in tlicir discoloration. Not only is there 

 aggregation of tlie protoplasm in the gland cells, but the walls of 

 the cells themselves become discoloured, and the glandular sur- 

 face of the pitcher that at first was of a uniform green, becomes 

 covered with innumerable brown specks (which are the discoloured 

 glands). After tlie function of the glands is exhausted, the 

 fluid evaporates, and the pitcher slowly withers. 



At this sta<>e I am obliged to leave this interesting investiga- 

 tion. That Nepenthes possesses a true digestive process such as 

 has been proved in the case of Drosera, Dionjea, and Pinguicula, 

 cannot be doubted. This process, however, takes place in a fluid 

 which deprives us of the power of following it further by direct 

 observation. "We cannot here witness the pouring out of the 

 digestive fluid ; we must assume its presence and nature from 

 the behaviour of the animal matter placed in the fluid in the 

 pitcher. From certain characters of the cellular tissues of the 

 interior walls of the pitcher, I am disposed to think that it takes 

 little part in the processes of either digestion or assimilation, 

 and that these, as well as the pouring out of the acid fluid, are 

 all functions of the glands. 



In what I have said I have described the most striking in- 

 stances of plants which seem to invert the order of nature, and 

 to draw their nutriment — in part, at least — from the animal 

 kingdom, which it is often held to be the function of the vece- 

 table kingdom to sustain. 



I might have added some additional cases to those I have 

 already dwelt upon. Probabl}^, too, there are others still un- 

 known to science, or whose habits have not yet been detected. 

 Delpino, for example, has suggested that a plant, first described 

 by myself in the Botany of the Antartic Voyage, CaUJia dlon- 

 occi folia, is so analagous in the structure of its leaves to Dionaen, 

 that it is difficult to resist the conviction that its stucture also is 

 adapted for the capture of small insects. 



But the problem that forces itself upon our attention is, How 

 does it come to pass that these singular aberrations from the 

 othervNise unifoim order of vegetable nutrition make their ap- 

 pearance in remote parts of the vegetable kingdom ? why are 

 they not more frequent, and how were such extraordinary habits 

 brought about or contracted ? At flrst sight the perplexity is 

 not diminished by considering — as Vv^e may do for a moment — 



