638 PHARMACEUTICAL BOTANY 
attracted by the presence of honey drops there. ‘They almost 
invariably run along its under side to shelter themselves from 
enemies and the hotsun. Moving on restlessly and sipping from 
nectar glands as they advance, they reach the tendril. The 
ventral wings and the areas between are more beset with alluring 
glands than is the outer part of the pitcher and along this they 
often run till they reach the orifice or lid. ‘The lid glands of the 
inner surface prove a greater attraction but their secretion does 
not compare with the marginal glands. Straining to reach the 
orifices of the glands, the insect visitors often overreach them- 
selves after a few efforts and tumble into the pitcher cavity, and in 
rare cases is escape again possible.” 
Mr. Low who accompanied Spenser St. John on his travels in 
North Borneo found a drowned rat in one of the pitchers of 
Nepenthes Rajah.' 
The character of the enzymes found in the pitcher secretions 
has been investigated by Hepburn.” ‘This author found a tryptic 
enzyme in Nepenthes which was active in a slightly acid medium. 
No proteolytic enzyme was found by him in the secretions of 
Darlingtonia while the Sarracenias he investigated were found to 
possess proteolytic enzymes. The protease in the pitcher liquor 
of Sarracenia flava and S. minor acts best in 0.2 per cent. hydrochloric 
acid while that present in S. purpurea, S. rubra, S. Sledgei and S. 
Drummondii acts best in an alkaline solution containing 0.5 per 
cent. or less of sodium carbonate. Dakin* found a protease in 
the pitcher liquor of Cephalotus. 
Tue BLADDERWORTS 
The bladderworts belong to the genus Utricularia. They are 
aquatic plants which are found in pools and bogs of various parts 
of the world with their centers in S. America and the East 
Indies. . 
The plants are rootless and according to the season of the year 
sink to, the bottom or rise to near the water surface. They have 
finely dissected submerged leaves, some of which are specialized 
Ree John, S.: Life in the Forests of the Far East, 1: 335-336, 1863. 
: Hepburn, St. John and Jones, Jour. Frank. Inst., 189: 152, 1920. 
Dakin: Jour. and Proc. Roy. Soc. W. Australia, 4: 37-53, 1919. 
