Chapter IV —57— Nepenthes 



the growth of the two parts is synchronous the sealing remains effec- 

 tive. During the last phase of development differences in growth cause 

 the Hd and pitcher mouth to separate and the former, as the result of the 

 growth of the isthmus of tissue between the hd and pitcher edge, is 

 hfted in many cases a considerable height above the mouth (7— 22, 23). 

 In its final position the lid may overhang the mouth, becoming a 

 more or less effective bar to the entrance of rain, especially in such 

 forms as N. Rajah Hook, in which the lid continues to grow and attains 

 a sufficiently large size to overshade the opening entirely. In other 

 species it remains small and narrow and turns completely back, fully 

 exposing the mouth of the pitcher (.V. ampidlaria Jack, .V. dubia 

 Dans.) (4 — 9), and though overhanging the mouth, is obviously 

 quite ineffective as a roof (A', incrmis Dans.). When the lid is large 

 and overhanging in position, it is thin, more or less emarginate, in- 

 dicating to Bower and to Macfaelane that the two halves of the lid 

 represent paired pinnae. In some species there is a median ridge on 

 the inner surface bearing numerous nectar glands (7 — 25), and in 

 other species there is a shallow invagination near the apex, the function 

 of which, if it has one, is not clear; or, as in .V. Ladenhurgii, there is a 

 short clavate projection. In .V. Tivcyi (and, says Macfarlane, in N. 

 maxima) there is a short, thick, glandular crest or ridge near the base 

 and near the apex a sharp thorn-like projection, hollow on its forward 

 surface (7 — 25). 



The under surface of the Hd is the seat of numerous nectar glands 

 except in a few species {N . ampidlaria, N. inermis probably). In 

 N. Lowii Hook., it is suppKed with many small appendages or bristles, 

 as Danser calls them, with nectar glands on the general surface be- 

 tween their bases. 



At or below the base of the hd on the outside of the pitcher stands 

 the spur. This, as may readily be ascertained by examining the young 

 pitcher during development, is the apical portion of the leaf (Hooker) 

 and it appears that the Hd is an outgrowth over the upper surface. 

 The spur is very small in some species and stands just at the base of 

 the lid {N. inermis). In N. bicalcarata, e.g., it becomes considerably 

 displaced downwardly, and stands out, quite suggesting a spur, from a 

 neck of tissue which raises the lid far above the opening {N. bical- 

 carata) (7 — 23). Sometimes the spur is compound and bears pinnae- 

 Uke laterals, suggesting lateral leaflets (Macfarlane) {N. ampidlaria, 

 N. phyllamphora) . 



Special anatomy. — The edge of the mouth of the pitcher is of dis- 

 tinctly pecuhar structure. It appears to be a parapet standing on the 

 edge, sloping inwardly on the whole, but with the outer margin some- 

 times turned more or less down. In a section of it made transversely, 

 it is T-shaped with the arms of the T of various lengths, according to 

 the species. In the majority both arms are of some length, so that the 

 parapet in such cases overhangs as much on the outside as on the in- 

 side, and with a general slope as much away as toward the opening of 

 the pitcher. N. ventricosa may be cited as an example of this con- 

 dition (7 — 16). In others (7 — 15, 17) the inner arm is short, 

 the outer long, while in .V. inermis (7 — 20) both are very short, the 

 outer a trifle longer than the inner. In N. Veitchii the width of the 



