Plants That Feed on Insects. 19 
nitrogeneous matter in a soluble condition, as bits of cork, 
wood, moss for examples, or bodies containing soluble nitro- 
geneous matter, if perfectly dry, such as small pieces of meat, 
albumen, gelatine, etc., may be long left on the lobes, and no 
movement is excited. But when nitrogeneous organic bodies, 
which are all damp, are left on the lobes, the result is widely 
different, for these then close by a slow and gradual move- 
ment and not in a rapid manner as when one of the sensitive 
filaments is touched by a hard substance. Small purplish, 
almost sessile glands, as has already been stated, thickly 
cover the upper surface of the lobes. These have the power 
both of secretion and absorption, but they do not secrete 
until excited by the absorption of nitrogeneous matter. No 
other excitement, as far as experiments show, produces this 
effect. When the lobes are made to close over a bit of meat 
or an insect, the glands over the entire surface of the leaf 
emit a copious discharge, as in this case the glands on both 
sides are pressed against the meat or insect, the secretion 
being twice as great as when the one or the other is laid on 
the surface of a single lobe ; and as the two lobes come into 
almost close contact the secretion, containing dissolved ani- 
mal matter, diffuses itself by capillary attraction, causing 
fresh glands on both sides to begin secreting in a continually 
widening circle. The secretion is almost colorless, slightly 
mucilaginous, moderately acid, and so copious at times in 
the furrow over the mid-rib as to trickle down to the earth. 
But all this secretion is for the purposes of digestion. Be 
the animal matter which the enclosed object yields ever so 
little, it serves as a peptogene, and the glands on the surface 
of the leaf pour forth their acid discharge, which acts like 
the gastric juice of animals. 
Now as to the manner in which insects are caught by the 
leaves of Dionwa muscipula. In its native country they are 
caught in large numbers, but whether they are attracted in 
any special way no one seems to know. Both lobes close 
with astonishing quickness as soon as a filament is touched, 
