Francis E. Lloyd — 32 — Carnivorous Plants 



the groove. But there is no conclusive evidence that the only apex 

 ever seen, the leaf-apex, is secondary, as in the case of Iris, though I 

 hesitate to deny the parallel accepted by Troll. 



In a leaf 0.8 mm. long (j — 16) the initial groove is surrounded 

 by a Hp which is evidently the rim of the pitcher, surrounding the 

 mouth. With further growth this is raised upward on a laterally 

 compressed stalk on the adaxial side of which the wing now appears 

 as a solid longitudinal outgrowth. In these later stages it is quite 

 evident that the margins of the leaf base meet transversely, and that 

 the wing arises quite independently of it. The zone between the lower 

 end of the wing and the upper end of the leaf base must, I think, be 

 regarded as petiolar. It is solid, and has unifacial structure. In the 

 mature leaf one can see that the wing is, near the mouth, slightly 

 doubled (j — 17, 18). 



Digestion and absorption. — It was once thought that the tubular 

 leaves were a device for holding water. Collinson wrote to Linnaeus, 



"the leaves are open tubes, contrived to collect rains and dews, 



to nourish the plant in dry weather." This prompted Linnaeus 

 to regard Sarracenia leaves as derived morphologically from those 

 of Nymphaea, but adapted to holding water for its needs, thus enabHng 

 it to occupy drier situations, incidentally providing water for thirsty 

 birds. But as Goebel, from whom we have drawn these notes, re- 

 marks, Sarracenia lives in swamps, a fact with which William Bar- 

 tram was familiar, but who yet thought that the water caught by the 

 hollow leaves was for the " refreshment " of the plant. 



Goebel, however, showed that it is easy enough to demonstrate 

 that the pitchers can and do absorb a not inconsiderable amount of 

 water: 6.8 cc. out of 20 cc, and 2 cc. out of 10 cc. in two cases. Fibrin 

 which he introduced remained unaffected, and meat extract, neutral- 

 ized with sodium carbonate, was attacked by bacteria. These and 

 other similar experiments led Goebel to the conviction that while 

 absorption can take place, there is no digestion beyond that attribut- 

 able to bacteria, and there is no antiseptic action. Previous to 

 Goebel several authors had expressed suggestions, opinions, even 

 convictions about the matter. Sometimes the remarks made did 

 little more than show that a question had arisen in the mind, as in 

 the case of Macbride (1817). Hooker (1875) merely recognized a 

 possibility that digestion occurs. Mellichamp (1875) was the first 

 to do some experiments which, though crude, led him to conclude that 

 the fluid of the pitchers hastens the decomposition of insects, without 

 at all evaluating the role of bacteria. Batalin (1880) interpreted the 

 exfoliation of the cuticle in the deeper zone of the pitcher as evidence 

 that in the absence of glands, which he incorrectly stated to be absent 

 from Sarracenia, digestive stuffs (Losungsmittel) for the solution of 

 proteins were released. No experiments to prove the occurrence of 

 digestion were done. Schimper (1882) showed that changes, due to 

 the absorption of food materials, occur in the epidermal cells similar 

 to the changes called aggregation by Darwin, but he could not find, 

 from experiments, that there is evidence of digestion aside from bac- 

 terial action. That nitrogenous compounds are absorbed was shown 

 by HiGLEY (1885). Zipperer (1885), concerned chiefly with anatomy, 



