J. M. Macfarlane. — Nepenthaceae. 



outward and run upward along the lateral and dorsal sides of the pitcher, tili they 

 approach the pitcher oriflce. The lateral veins, as well as the upper ends of the ventral 

 ones then curve gracefully round toward the dorsal region, and in their course give 

 off minor bundles that run up into the substance of the thick corrugated peristome. 

 Here each bündle divides along the inner margin into still smaller bundles that Sur- 

 round the marginal glands of the rim. The recurved lateral and the dorsal veins 

 converge and thin out toward the point of insertion of the lid, into which they give 

 off two main veins. Their now attenuated extremities end in the dorsal spur, situated 

 behind and near the point of insertion of the lid. This 

 spur has therefore generally and rightly been regarded as 

 the organic apex of the entire leaf System. 



A noteworthy relation of the veins of the pitcher is 

 that every gland, whether external or internal in Posi- 

 tion, has a bündle termination endin g in or around it. 

 This can be beautifully demonstrated to the naked eye, 

 by macerating a pitcher in hot potash Solution for 20 — 

 30 minutes, and then removing the outer and inner epi- 

 dermis in water. The looser mesophyll tissue readily 

 washes away, and the bündle twigs that supplied the 

 glands appear as fine branch terminations of the vas- 

 cular network of the pitcher. 



The alluring glands of the leaf are readily visible to 

 the naked eye, and are more or less developed from the 

 base of the petiole to the peristome and the outer lid 

 surface. Their microscopic structure is described later 

 (p. \ 7). In such species as N. ampullaria and N. Ttaf- 

 flesiana they are scarce over the petiole and lamina, but a 

 few may be observed along the sides of the lower midrib 

 surface, as minute papillär swellings that exude a sweet 

 juice in fresh leaves. They are somewhat more abundant 

 over the pitcher wings, less so over the dorsal part of the 

 pitcher. In N. Veitchii, N. khasiana, and N. maxima 

 they are frequent over the petiole and lower laminar 

 surface. In N. Northiana and N. sanguinea they are 

 also found on the upper laminar surface, the tendril and 

 the pitcher. But in N. bicalearata they attain largest 

 size and are quite abundant. Here they offen form con- 

 spicuous warts along the sides of the petiole, the midrib Fig. 4. Nepenthes gracitis Kovlh. 

 and the tendril. These glands , in conjunction with the Extremity of lamina with midrib 

 alluring glands of the stem, tempt insects upward by prolonged into a tendril or cir- 

 their secretion, to the pitcher mouth or to the lid. In rhus M? that ex P ands into a 



hot dry weather the sweet secretion may even dry, so 



pitcher shown in section; e oper- 



, culum in section, d corrugated 

 as to appear as a fine white vermiform thread attached peristome) c deep conducting 



to the oriflce of the gland. surface; b detentive and d i gesUve 



The peristome or corrugated rim of the pitcher surface with digestive glands. 



(Fig. bd) is a conspicuous feature in nearly all species of (After Sachs.) 



the genus. N. Lowii (Fig. \ 9) is the only species in which 



it is undeveloped, the pitcher margin being straight and somewhat reflexed. Along its 



inner margin are fine parallel longitudinal ridges, that indicate vascular bundles tra- 



versing the internal tissue. Each ends below the edge in a deeply sunk marginal 



gland that opens by a small papillär pore. The pores collectively form a dotted line 



about 4 — 6 mm beneath the edge of the pitcher. The typical peristome is formed in 



part from incurving of the margin, which up to the period of opening of the young 



pitcher is a uniform rim that projects upward under the closely fitting lid. In part 



