Chapter II —25— Sarracenia 



In this early stage the structure resembles that of Darlingtonia, save 

 for the forward developing fishtail appendage, which here does not 



appear at all. 



The interior surface of the pitcher presents a zonation which cor- 

 responds roughly with that in S. purpurea, but is by no means as 

 distinct as in that species. This lack of distinction arises from the 

 overlapping of the zones 3 and 4, and the restriction of zone 2 to the 

 inner surface of the entrance tube, the ventral portion of which is part 

 of the pitcher tube proper. This point must be appreciated as other- 

 wise it would be difficult to recognize zone 2 at all. 



Zone I (j — 4) is the whole of the inner surface of the hood ex- 

 cepting the inturned edge of the re-entrant tube. The epidermis is 

 of wavy-walled cells with stomata and many nectar glands, and scat- 

 tered, relatively few downwardly directed, curved weak hairs, as com- 

 pared with the flap of 5. purpurea, or Heliamphora. Since the chief 

 mechanism for the capture of insects is the re-entrant tube, these hairs 

 are of little importance. This is compensated for by the presence of 

 very many stiff hairs in the dorsal aspect of the dome, to which zone 

 3 reaches. 



Zone 2 corresponds to this zone in S. purpurea in function, though 

 it is not a complete zone geometrically speaking. It embraces a short 

 reach of the ventral wall of the pitcher with the contiguous sides of 

 the re-entrant tube, including the shelf, which is within the morpholog- 

 ical edge of the lobe. The shelf and the inner surface of the tube 

 sides are clothed with an epidermis of tessellated straight walled cells 

 each with a low striated umbo, pointing inward and downward, as in 

 zone 2 of S. purpurea. Glands are present, in greater number proxi- 

 mally than distally. They are absent under the shelf, but the shelf 

 itself bears a great many. This is the principal lure evidently, but the 

 insect which advances into the re-entrant tube to sip the nectar is 

 invited to enter further by the shining white fenestrations, mullioned 

 in red, of the pitcher wall. The outer surface bears many small glands 

 also, which, with those of the general outer pitcher surface, constitute 

 a general lure. 



Zone 3. Like zone 3 of 5. purpurea this carries some stomata and 

 many glands, but, unlike that species, the whole surface is clothed 

 with a dense felt of downwardly pointed, slender stiff hairs, continuous 

 with those of zone 4. It may be described as an advance of zone 4 

 to overlap zone 3. The parallelism between this species and S. pur- 

 purea is seen in the many glands of this zone. These are possibly 

 peptic glands, though the evidence is at present not conclusive {see 

 p. 34). The epidermis is of a mixture of wavy- walled cells, and smaller 

 straight walled cells, these becoming more numerous as the next zone 

 4 is approached. It is underlain by a course of wavy-walled cells, the 

 walls of which are thick and afford stiffening to the pitcher wall._ 



Zone 4 is devoid of glands, but has a dense clothing of trapping 

 hairs down to the very end of the pitcher tube, where they are shorter, 

 fitting better the reduced bore of the tube, and leaving a lumen. 

 Macfarlane described the whole of zones 3 and 4, as above delimited, 

 as the detentive zone, but having glands in the upper one-third. In 

 S. purpurea zone 3 is secretive, and has a glissade surface, while in 

 S. psittacina the surface is hairy. 



