Francis E. Lloyd —60— Carnivorous Plant s 



lower moiety of the blade with a similar condition found in N.^ clipeata 

 Dans., points out that the resemblance is but superficial, since the 

 Codiaeum leaf is petioled while the ''blade" of Nepenthes is more 

 probably an expansion of the leaf base (Blattgrund) to be compared 

 with the primary leaf of Pothos. Goebel also held the view that the 

 pitcher is a peltate leaf developed into a tubiform one, and compared 

 the pitcher of Nepenthes with that of Utricularia, which is also ter- 

 minal either to a single "leaf" {Polypompholyx, Utricularia Menziesii, 

 etc.), and has a lid (door) which springs laterally from the true apex of 

 the trap visible as such in some species, e.g. U. Welwitschii, or to a leaf 



segment. 



5. The leaf of Nepenthes is not simple but compound. According 

 to Bower the lid arises as a double organ, the two congenitally fused 

 (^_ 4) ^ and represents two leaflets. This was based on embryological 

 observations. Macfarlane went still further and claimed to be able 

 to analyze the whole leaf into "3 to 4 or 5 pair of leaflets", the basal 

 lamina, the wings on the ventral surface of the pitcher, the lobes of the 

 Kd (Bower), and one or two pairs of lateral appendages sometimes 

 occurring on the spur, which itself terminates the leaf. This idea goes 

 back to Ch. Morren (1838) (Goebel 1891) who regarded the leaf as 

 having fused foholes and the lid as a terminal leaflet. Goebel (1923) 

 remarked that this view might have been entertained if, in the circle of 

 relationship, plants with compound leaves were known. 



6. Troll put forward the theory that the Nepenthes leaf is a com- 

 plete parallel to the ordinary foliage leaf consisting of a basal zone 

 (Blattgrund), a petiole, and blade which is the pitcher (Oberblatt) 

 disturbed, however, by a modification of the petiole whereby it is at- 

 tended by a displacement upwards of the edges of the leaf base to 

 become the wings of the pitcher. Such a displacement occurs in Syn- 

 gonium podophyllum, and I have shown (1914) that it occurs in Gos- 

 sypium in which the flower peduncle normally suffers displacement up 

 the internode above, bringing the flower into an unusual position. 

 More specifically, Troll sets forth that (7) the leaf base consists of a 

 clasping bottom leaf zone which is contracted briefly to reexpand to 

 form the conspicuous lamina, and which in some species extends at its 

 apex across the base of the tendril in total stipulation {N. clipeata, 

 and others). (2) The blade is differentiated into the petiole and true 

 leaf blade. The former takes the form of a tendril, the latter the 

 pitcher, the blade in peltate form. But here the relation between the 

 petiolar structure and the peltation does not behave so simply as in 

 simple peltate leaves, (j) The spur is unifacial (as in Pothos). Arber 

 (1941) questions this view. At its base, the edge of the blade grows 

 to form a transverse connection from which the lid arises. This again 

 is total stipulation. 



The supporting evidence is now briefly stated. (/) In the first 

 place the tendril is of bifacial structure (Troll) {8 — 20), and not, as 

 C. P. de Candolle (1898) thought, unifacial. The arrangement of the 

 fibrovascular bundles is not concentric with respect to phloem and 

 xylem, since the wood faces ventrally in the ventral moiety of the 

 organ. I can confirm this. (2) Reexamining the embryology of the 

 leaf, it is clear that in the primary leaf (in seedlings) the thinned out 



