APPENDIX 



and falls into the well prepared to receive it. Once in there it cannot 

 escape, and is drowned in the liquid always accumulated therein, which 

 has been secreted by the plant even before the opening of the pitcher. 



The plan followed by Nature in the production of the ascidia of the 

 Nepenthes, is, as I read it, the following one : — Originally the primordial 

 dilatation of the leaf organs, from which the pitcher is derived, was caused 

 by the necessity of storing water, supposing that the Nepenthes were 

 aquatic plants in early epochs, transformed later into epiphytal or terres- 

 trial species. 1 According to this view the ascidia would have been 

 merely internal reservoirs for water, swollen by tension, which eventually 

 breaking at a given point, formed the lid or operculum, in a manner 

 analogous to that of the " urns " of the mosses. Into the open cavity 

 containing water thus formed, insects accidentally fell, and subsequently 

 the stimulus of organised matter in contact with the walls of the pitcher 

 may have produced in the protoplasm of its peripheral cells (by reversion 

 towards primitive voracious instincts) an avidity for nitrogenous sub- 

 stances, whilst the visits and stimuli of insects would have induced the 

 development of glands secreting saccharine substances, and would have 

 given origin to the appendages which surround the lips of the ascidium. 



Formerly it was thought that the insects fallen into the pitchers of 

 the Nepenthes by putrefying in the liquid therein collected, indirectly 

 furnished to the plant nitrogenous substances useful for its alimentation. 

 But recent investigations have proved that this is only exceptionally 

 true, and that normally the Nepenthes secrete, by means of certain glands 

 placed internally in the lower part of their " pitchers," a digestive fluid, 

 and the same glands afterwards subtract the assimilable matter from 

 the bodies of the ants and other insects captured, not through putrefaction, 

 but b}^ a true process of digestion. The Nepenthes are thus to be placed 

 among those plants which have been aptly termed carnivorous. It is 

 not however proved that in order to live and prosper the Nepenthes 

 must necessarily digest animal substances, and many a time these plants 

 are found without a single insect caught in their pitchers, and yet they 

 do not appear to suffer. This nearly always happens to the Nepenthes 

 cultivated in European hothouses. 



Carnivorism in plants is, I think, to be considered rather as a vice 

 than as a functional necessity. Indeed, it does not appear that they 

 have derived any great and special advantage over normal-feeding plants 

 by this extraordinary faculty, which in a certain way brings them near 

 to the higher animals. Animal food is beyond doubt a luxury for 

 carnivorous plants, and they can perfectly well do without it, precisely 

 as a number of human beings have existed until now, and could still 

 continue to exist, without spirits, tea, coffee or tobacco. 



Floral Areas in Borneo. — The Bornean Flora assumes multiform 

 aspects, and its components are of a varied nature according to the 

 localities, the elevation, and the physical conditions of the soil. Thus 

 distinct areas of varied extent can be recognised, some much restricted, 

 on which a special vegetation grows, different from that of adjoining 

 lands. Such floral areas, which might even be styled "botanical 



1 Cf. Malesia, vol. i., p. 233. 

 408 



