MISSOURI BOTANICAL GARDEN BULLETIN 63 
covers the orifice of young pitchers but lifts as a hinged lid 
when the pitcher is matured.1 
The pitchers vary in size from one and one-half to twenty 
inches in height. For the most part they are highly colored, 
displaying a yellowish green ground, marbled and veined 
with purple. Many are of a bluish, violet, or rose tint near 
the orifice, or sometimes dark red; from a distance they have 
the appearance of flowers, and, like flowers, are sought by 
insects. Furthermore, they secrete an abundance of nectar 
from the under surface of the lid and on the rim about the 
~ mouth of the pitcher. Insects which sip this nectar wander 
only too readily to the interior of the orifice. Here the inner 
face is smooth and so slip as to afford no foothold, and 
the insect slips down to the Bottom of the pitcher into the 
secreted liquid, and ultimately perishes. 
The liquid, which fills one-third to one-half of the cavity, 
is secreted by special gland-cells on the inner surface of the 
pitcher, is of a slimy, tasteless character and gives a neutral 
reaction. As soon, however, as an animal’s y comes in 
contact with it, or even as the result of a mechanical stimulus, 
the reaction of the liquid is rendered acid, and in this condi- 
tion the fluid possesses the power of dissolving albuminous 
substances, such as flesh And ooaphlalie blood, functioning, 
therefore, like the gastric juice of the animal’s stomach. 
Furthermore, the products of the digestion appear to be 
promptly absorbed by the leaf. The process taking place 
when animals fall into the liquid contained in the pitchers 
of the Nepenthes species may therefore be properly desig- 
nated as digestive. 
Pinguicula, or butterwort, is native to the Arctic and Sub- 
arctic regions and the high mountains of the temperate zone. 
The leaves form a rosette, the under surface of which rests 
upon the wet ground. The margins of the leaves are some- 
what upturned so as to form a broad flat-bottomed trough, and 
the upper surface is covered with innumerable microscopic 
glands which secrete a colorless, sticky liquid in great abund- 
ance. The latter acts as a trap in the same manner as aged 
fly-paper. When an insect becomes entangled in the mucil- 
age covering of the leaf the glands are forthwith stimulated 
to a more profuse secretion of fluid, which has an acid re- 
action and contains a protein digesting enzyme, or ferment, 
the conditions apparently being much like those in the 
pitcher-plant. At the same time the margins of the leaf 
gradually roll upward and inward, forcing the insect toward 
* A good illustration of one of the specimens in the Garden accom- 
poe the article on Nepenthes in the October, 1913, number of the 
