Francis E. Lloyd — 4 — Carnivorous Plants 



probability to be a carnivorous plant by Miller Christy (1923). 

 This biennial herb is well known for its water catching reservoirs formed 

 by the connation of the opposed leaves at their bases. A large plant 

 attains a height of 6 feet. Eight plants, with an average height of 5 feet 

 8 inches, were found by Christy to retain an average of a half pint of 

 water. It is of interest to know that the teasel for this reason claimed 

 the attention of Turner (1551), who remarked the catching of "rayne" 

 and ''dew" (Herball, o.iiij, 1551) and Gerard (Herball, p. 1005, 1597) 

 wrote quaintly, as it now appears to us, "The leaves growe foorth of the 

 iointes by couples, not onely opposite or set one against an other, but 

 also compassing the stalke about, and fastened togither, and so fas- 

 tened that they hold deaw and raine water in manner of a little bason." 



Christy rejects the ideas that the primary object of the collection 

 of water is the succour of the plant in times of drought, and the pro- 

 tection of its nectar from predatory insects. The presence of dead in- 

 sects, rendering the water filthy, seems to point to these as a source of 

 nutriment. "The cups undoubtedly form most efficient traps," Fran- 

 cis Darwin had said. Christy suspected the water to have some 

 narcotizing or intoxicating substance (F. Darwin had noticed that 

 beetles drown in it more rapidly than in pure water), and he further 

 expressed the conviction that "the plant does profit by the insects 

 caught in the cups". In view of the general evidence Christy draws 

 the conclusion that the teasel is a carnivorous plant, but without ad- 

 vancing any definite experimental proof. 



The lobster-pot of Genlisea, though an exceedingly specialized 

 structure, is fundamentally nothing more than a narrow pitcher with its 

 interior armed with downward pointing hairs. Even the curious 

 method of holding the lips of the narrow slit-like mouth in rigid rela- 

 tion to each other by an adhesion of cells finds its parallel in other 

 situations such as the adhesions of algal cells and those of mycelia. 

 In form, the 'prop-cells' responsible find a loose analog in the cystidia 

 of Coprinus. But, after all, their structure and method of function is 

 unique. 



The snares found among the carnivorous fungi — those having def- 

 inite traps — are more obscure in their analogies, and, it would appear, 

 have originated within the group. Apparently unique is the noose of 

 Arthrobotrys, etc. The adhesive disc is found among the orchids, in 

 which it is the mechanism for attaching the pollinia to visiting insects. 

 Obviously the orchids did not invent this originally — the fungi prob- 

 ably did so. The loop of the pollinia of Asclepias is a sort of noose 

 snare (Carry). 



The snare of Zoophagus is a variant of the adhesive disc, but is re- 

 markable as a device resembling in its manner of working a common 

 fish-line and hook, or perhaps better an 'eel-bob.' 



The plants which catch their prey by means of a viscid secretion 

 are only a few of a multitude of others that excrete sticky substances 

 by which small insects are caught. These substances are in general of 

 three kinds: oily (often aromatic), resinous and mucilaginous. Among 

 the carnivorous plants, only the last is found, as a watery medium is 

 the only one that can carry an enzyme, as in Drosera. Adhesive (mu- 

 cilaginous or resinous) glands are very common, and often small insects 



