Francis E. Lloyd — 68 — Carnivorous Plants 



amined held a collection of ants which must have run into the thou- 

 sands. With regard to the ability of flies (houseflies and blue-bottles) 

 to retain a foothold on the rim, my friend Professor A. H. Reginald 

 BuLLER repeatedly observed many years ago that, in trying to 

 straddle the rim, they promptly fell into the pitcher, in N. Master- 

 si ana. 



BoBisuT further thought that the curious deformed stomata could 

 furnish a foothold for the claws of the ants, etc. but Knoll showed 

 that the conformation, position and size of the ant's claws and of the 

 apparently available points for grasping with claws make them un- 

 available. From the ant's point of view the projecting guard cells 

 should have been turned the other way. Haberlandt thought that 

 they helped an insect to crawl downward but not upward, since they 

 afforded no foothold for the claws, but since the claws are not used, 

 but the pads only (Knoll), and since ants cannot climb downwards 

 any better than upwards on the surface, Knoll, not being able to 

 avoid the impression that the stomata are in some way connected 

 with trapping of insects, has advanced the following suggestion, namely, 

 that the numerous projecting guard cells serve, when the waxy surface 

 has more or less been removed by various means (rain, much traffic of 

 insects), as a means of joggling the body of the ant by the slipping of 

 a foot over them, somewhat as when, on climbing on a steep, precarious 

 rocky surface, a hand should slip from its hold of a ledge and slap the 

 rock surface just below. " Riitteleinrichtungen " Knoll calls the 

 projecting half-moon shaped cells, and regards them, briefly, as an 

 arrangement for hindering the climbing of the walls of the slipping 

 zone (Hooker's conducting zone). It must be remembered that an 

 ant uses its footpads and not the claws in trying to climb a smooth 

 surface. The frequent irregularities in form of the surface make it the 

 more perilous, according to Knoll. The theory is ingenious and may 

 very well represent the facts, which to Knoll are such in view of his 

 observations. 



Below the slide or conducting zone, when present, the whole of the 

 remaining surface constitutes the detentive or digestive zone {4 — 6) . 

 It is a glossy green or red (A^. ventricosa) in color, and stands out in 

 sharp contrast with the glaucous color of the waxy zone above. The 

 surface is richly supplied with glands. Each gland stands in a slight 

 depression, the upper edge of which projects and overhangs the gland like 

 an eave, sometimes slightly, more often covering at least half the gland 

 {8 — 10, 11), or in the case of N. Pervillei (7 — 14) forming a deep pit. 

 In the depths of the pitcher, the glands often become more or less ir- 

 regular in shape and are devoid of any overhang (Macfarlane, Stern). 



There seems to be every reason to regard these glands as both diges- 

 tive (or peptic as Macfarlane called them) and absorptive. Their ac- 

 tivity becomes evident long before the pitcher reaches its maturity, 

 young unopened pitchers always having the cavity half-filled with 

 fluid. Later a plentiful additional secretion occurs when organic, but 

 not so plentiful if inorganic materials are placed in the pitcher 

 (Hooker). That they are capable of reabsorbing the fluid is evident 

 in the fact that in a rather short time (24 hours or so) the fluid may 

 entirely disappear from unopened pitchers (de Zeeuw), and Goebel 



