Francis E. Lloyd — 58 — Carnivorous Plants 



rim towards the lid is so great (up to 60 mm, says Danser) as to bear 

 a likeness to a "Marie Stuart collar" (de Ruiter 1935). The greatest 

 reduction of the inner arm is found in N. Lowii (7 — 18), which has 

 been described as without a peristome (Danser). There is, however, a 

 row of glands embedded in tissues which project to form a slight, 

 interrupted shelf while the outer arm is of some width relatively. At 

 the other end of the series stand such forms as N. hicalcarata, N . 

 intermedia and A^. ampullaria (7 — 19), in which the outer arm is very 

 short and tightly reflexed and the inner very long; in these species the 

 peristome has a very pronounced funnel shape. In N. ampullaria, 

 which forms rosettes of pitchered leaves on the forest floor, the pitchers 

 partly buried on the humus, the whole constitutes a group of pitfalls, 

 each with a broad overhanging edge which would prevent escape quite 

 effectively in many cases. 



Of the two arms of the T, one, the outer, represents the true 

 pitcher mouth edge, outwardly reflexed. The inner arm is an out- 

 growth from the inner wall near the edge. This is easily seen to be 

 the case in young pitchers during their development (Heide, 19 10) 

 {8 — 19). In any case it can be seen that the vascular tissues of the 

 inner arm are derived by sharp branching from the main trunks which 

 extend to and along the edge proper. 



But although the peristome is composed as it were of two flanges, 

 an outer, the edge of the pitcher mouth, and an inner, growing out as 

 a ridge from the inner wall, the whole during late development is so 

 moulded that the two flanges are amalgamated to constitute a single 

 organ, the inner surface of the edging flange and the outer surface of 

 the side flange becoming a continuous uninterrupted surface. The 

 whole is mechanically very rigid, for it is strengthened by a very thick 

 cuticle and the surface is broken up into minute striae and coarser 

 corrugations (4 — 11). The latter give the peristome their ribbed 

 appearance, and their most pronounced expression is reached in N. 

 villosa Hook. On the inner edge of the peristome the corrugations 

 end in minute teeth, and between each pair of teeth (7 — 21) there is 

 an opening, the mouth of a large nectar gland which lies buried in the 

 tissues. The nectar oozes in a drop held between a pair of teeth, of 

 access to insects standing on the rim and reaching down. This ar- 

 rangement together with the nectar glands on the under side of the 

 lid constitute a lure, the ''attractive zone" of Hooker. The hard, 

 glossy surface of the peristome is not, as it may seem to the eye, a 

 smooth, slippery one, for as a matter of observation, small insects 

 (ants, etc.) can walk freely on it, using their footpads. When the 

 tissues below the base of the lid are considerably extended, as they 

 are in A^. hicalcarata and N. intermedia (7 — 22, 23), the peristome is 

 extended likewise, and in these two cases, but only in these, there is, at 

 its extreme upper ends which are separated by the base of the lid, a 

 very strong development of the last dozen or so corrugations to form 

 two long sharp thorns, resembling the canine teeth of a cat. In 

 A^^. hicalcarata, these are long, solid, curved, very sharp and distinctly 

 canine in appearance. A rather fanciful explanation of the use of these 

 was advanced by Burbidge (1880) who pointed out that the Tarsius 

 spectrum, a small, insectivorous, monkey-like mammal, "visits the 



