Francis E. Lloyd — 54 — Carnivorous Plants 



is a pinnate structure obscured by secondary changes. They are more 

 or less conspicuous on mature leaves in some species {N. ampullaria) 

 while on others the spur, as it is called, is a tapering simple conical 

 projection often much displaced by the secondary growth of the tissues 

 beneath it so that the lid is moved forward to occupy an apparently 

 terminal position (4—10; 7 — 23). Meanwhile the leaf blade de- 

 velops more or less in front, i.e. on the ventral surface, of the enlarging 

 ascidium in two usually deep ridges, the margins of which are con- 

 tinuous to the base. From their position it appears clear that the 

 ascidium is formed by the expansion chiefly of the lower moiety of 

 the midrib, so that at full growth the leaf margins mark the limits of 

 the upper surface of the midrib. 



In adventitious shoots produced by forcing cuttings, good material 

 of which I obtained at Munich, various embryonic conditions of the 

 leaf are preserved in the mature condition, which are always small 

 and embryonic ("juvenile") in appearance as in fact. This is to be 

 referred to the failure locally of the incidences of growth which would 

 mold the leaf into the mature form, such as the failure of the leaf to 

 elongate in the region giving rise to the tendril; or the continuation of 

 growth where it is normally suppressed, such as in the narrowing of 

 the blade at the base of the ascidium. The former is shown in Fig. 

 7 — II which is nearly mature, the leaf blade being here narrowed in 

 the region which in a completely developed leaf would have become 

 the tendril. The second condition is shown in Fig. 7 — 13 in which 

 it is seen that the leaf blade has expanded, beginning to do so at the 

 middle point of the ascidium instead of below the base. In both these, 

 as in other early stages of development, the apparent "two-lobed" 

 condition of the lid, seen by Bower and others, stands out. That this 

 is more than appearance may be doubted. It may be contended that 

 the lobing may be an appearance due merely to the infolding of the 

 middle longitudinal zone, the marginal zones resting on the rim of the 

 pitcher, which during the earlier stages of development is laterally 

 compressed so that the sides of the mouth, that is of the rim, are 

 close together and parallel (7 — 24; 8— 19). The presence of emargi- 

 nation is not by any means general, and at best, as Goebel points out, 

 its presence is not an indication of lobation. In any event emargina- 

 tion may easily occur when it does, from the manner of longitudinal 

 folding by mutual pressure of the rim and Hd apex. 



The spur (we continue to treat of juvenile leaves of short shoots) 

 is usually broad and lobed, and, being the organic leaf apex (Hooker) 

 receives the terminal part of the mid vein, which does not pass into 

 the lid, so that this is devoid of a midvein (7 — 7-10). Below the base 

 of the spur, however, the midvein of the pitcher may send anastomoses 

 joining it with lateral veins. The venation of the spur is made up 

 almost wholly of lateral veins derived from far down at the base of the 

 pitcher, swerving around from back to front, and then back again 

 below the rim. In specimens resembling the more adult type of 

 pitcher, veins appear in the lid which, though suggesting a midvein, are 

 really branches and anastomoses between the laterals and the midvein 

 (7 — 9; Text fig. 2, p. 63). 



The mature leaf may in some species attain a length of one to 



