Francis E. Lloyd — 44 — Carnivorous Plants 



zone of each lobe of the fishtail is a continuation of the nectar roll 

 on its own side. Its position and topographical relations in the defini- 

 tive pitcher leaf show that it gets these as a result of torsion and con- 

 traction of the tissues at its base. I have been prompted to make 

 a guess as to what a primitive condition of the Darlingtonia leaf might 

 have been. Plate 6 — 13 represents such a hypothetical condition. 

 In order to get B, which with a little more forward curvature would 

 represent the modern pitcher, all that need occur is the transverse 

 contraction of the base of the flap accompanied by bending forward. 

 It should be noted that there is no fusion of the two sides of the nec- 

 tar roll in front, so that the inner superficies of the hood are con- 

 tinuous through the gap between the forward ends of the two sides 

 of the nectar roll with the ventral (upper) surface of the fishtail. That 

 a change of this nature has occurred in the process of evolution is 

 indicated by the case above mentioned of a juvenile leaf with a nectar 

 roll and an emarginate apex, but not contracted transversely at its 

 base (5 — 3). In this case the edge of the nectar roll is clearly con- 

 tinuous with the edge of the apical appendage. This is an objective 

 example of the hypothetical primitive condition presented in 6 — 11. 



The fishtail appendage on its outer (dorsal) surface has stomata 

 and simple glands in great numbers. The inner or ventral surface has 

 no stomata, but there are numerous glands, and a good many stiff, 

 thick, blunt hairs turned morphologically downwards, but, because of 

 the upsidedownness of the hanging appendage, point upward and 

 furnish a rough surface which assists, rather than impedes, a climbing 

 insect, lured by the abundant nectar. To the presence of this there 

 is abundant evidence in the living plant. The converging folds of 

 the appendage, as an insect crawls upward, {4 — 5; 5 — 9), guide it 

 toward the entrance into the hood, where it meets the inturned nectar 

 roll. Once inside, the insect has to face the dangers of the inner 

 surface. It is not to be supposed that insects will insist on using the 

 appendage. Nectar glands occur everywhere on the outer surface. 

 The ventral wing, as well as the appendage, may act as a wing-fence 

 to guide them to the opening. Meeting the heavy exudation of nectar 

 on the nectar roll is an added spur to entrance, however they may 

 have been attracted thus far. 



To turn to the conditions found in the interior of the pitcher. The 

 forward (upper) portion, the dome, is lined with many stiff, coarse 

 hairs so directed as to urge insects toward the depths of the tube. These 

 are largely absent from the areolae, though small ones may occur. 

 They are most plentiful on the floor, where there are no areolae. In- 

 termingled with the hairs are many nectar glands, so that the whole 

 forward portion of the floor of the dome serves as a feeding ground, 

 from which also insects can feed with great convenience on the nectar 

 roll, as from a table. The rear of the dome, however, the surface of 

 which extends down into the tube, has no glands, but the imbricated 

 epidermal cells are elongated, each into a sharp downwardly pointed 

 hair, which offers no foothold. This continues far into the tube, as 

 far as a point where there are no more fenestrations in the wall. Here 

 the character of the hairs gradually changes, and they become fewer 

 and longer. In the extreme depth of the tube the hairs are absent. 



