42 1 
Insectivorous Plants (Part II). 
That this is no mere hypothesis is proved alike in the develop- 
ment of seedling-leaves and in the young state of adult leaves, 
for in all that I have examined the marginal glands first 
appear and attain the largest size ; simultaneously with them, 
though greatly simpler in structure, the internal ‘ digestive ’ 
glands ; thereafter appear a few alluring glands on the general 
leaf-surface ; and last, when present, the attractive lid-glands 
are developed. 
But a study of the species of Nepenthes at present known 
leads one to conclude that, excepting two or three which have 
early branched off from the primitive type, all can be naturally 
connected with each other by easy gradations. I shall now 
shortly pass these in review, and note points of interest in each. 
In N. ampullaria the pitcher is tubular, its broad corrugated 
collar is so abruptly curved into the pitcher-cavity as to be 
quite parallel to its walls ; the lid is tilted back at an angle of 
about uo°-i3o°. Only in one or two instances have I ob- 
served alluring glands on the outer lid-surface ; the marginal 
glands are of small size and ampullate in shape ; the conducting 
surface, represented by a narrow glabrous band internally at 
the top of the tube, is functionless, and small digestive glands 
thickly cover the whole inner cavity 1 . 
In N. Hookeri the pitcher is tubular or globose ; its orifice 
is surrounded by a narrower collar than in the last, and the 
collar is inclined at an acute angle to the cavity ; the lid is 
greatly larger, and is vertical or slightly inclined over the 
pitcher-mouth. A few alluring glands are present, and the 
inner lid-surface may either be devoid of glands or have from 
ten to thirty along the grooves of the lid. The marginal 
glands are ampullate, and decidedly larger than those of the 
last species, though the conducting and digestive surfaces 
remain the same. 
In N. Rafflesiana the pitcher is tubular and globose or 
cornucopia-shaped ; the corrugated collar is relatively narrower 
1 It will be seen that even in this species a marked advance on the primitive 
type is shown in the possession of so deep a corrugated rim, which imperfectly 
functions, instead of the more specialized conducting surface of the higher forms. 
F f 2 
