Below the lid is the conducting surface of glassy epidermal cells, with short downward-directed points, which facilitate the descent, but impede the ascent of an insect. Then come the glandular sur upon the pitcher itself, some drop their eggs into the putrescent mass, where their larvae find abundant nourishment, while birds often slit open the pitchers with their beaks and devour the mag gots in their turn.
Cephalotus follicularis, a native of south-west Australia, a small herbaceous plant, bears ordinary leaves close to the ground as well as pitchers. The latter somewhat resemble in general form face, which is formed of smooth polished epidermis with numerous glands that secrete the fluid contents of the pitcher, and finally the detentive surface, of which the cells are produced into long and strong bristles which point downwards and meet in the centre of the diminishing cavity so as to render escape impossible. The secretion wets an insect very rapidly, but its digestive power is uncertain. The pitchers accumulate vast quantities of insects in the course of a season, and must thus abundantly manure the surrounding soil when they die. Moreover, the feast is largely
shared by unbidden guests. Not to speak of insects which feed those of Nepenthes. The lid is especially attractive to insects from its bright colour and honey secretion ; three wings lead up to the mouth of the pitcher, on the inside of which a row of sharp spines points downwards, and below this a circular ridge armed with papillae serves as a conducting area. A number of glands on the interior of the pitcher secrete a fluid in which insects are found but how they are utilized is still obscure.
For further details, see K. GObel, Pflanzenbiologische Schilderungen (Marburg, 1889-93) ; F. Knoll, "Ober die Ursache des Ausgleitens der Insektenbeine an wachsbedeckten Pflanzenteilen," Jahrb. f. wiss. Bot. (1914) ; J. S. Hepburn, "A Study of the Protease of the Pitcher Liquid of Nepenthes," Contrib. Bot. Lab. Univ. Penn. (1919) ; P. van Oye, "Zur Biologie der Kanne von Nepenthes melamphora," Biol. Centralbl. (1921).