ECOLOGY 625 
become covered with the sticky substance which occludes the 
orifices of their breathing tubes (tracheae) and they perish in a 
short time (one-quarter of an hour according to Dr. Nitschke) 
from suffocation. The surrounding tentacles bend over the 
insect’s body and clasp it on all sides. A digestive juice con- 
taining a proteolytic enzyme of peptic character and an acid is 
now poured out of the glands. This digests the flesh and blood 
of the insects caught. The water-insoluble chitinous parts of the 
body are left on the surface of the blade. If the insect be large, 
the bending of the tentacles is augmented by the inflexion of the 
whole surface of the leaf-blade which assumes a concave shape. 
With the tentacles also curved over, the whole leaf simulates 
a closed fist. The glands then absorb the soluble nitrogenous 
material which is assimilated by the plant. 
Among the insects caught by the sundews are gnats, flies, ants, 
beetles, small butterflies and dragon flies. The last named are 
captured by the cooperation of 2 or 3 adjacent leaves. 
Tue Fry Traps 
The fly traps comprise two species, viz.: the Venus Fly Trap 
(Dionea muscipula) and the Submerged Dionzea (Aldrovanda 
vesiculosa). 
The Venus Fly Trap is restricted to damp localities of a coastal 
plain strip extending for about 55 miles north and 45 miles south 
of Wilmington, North Carolina, and nowhere over 15 to 20 miles 
in width. an 
_ Each plant shows a rosette of modified leaves which together 
are rarely more than 6 or 7 inches across. From the center of 
these arises a flower stalk bearing a cyme of white flowers which 
open from April to June. 
Each leaf consists of a winged petiole that is studded on both 
surfaces with small, brown, stellate hairs. The petiole is trun- 
cated in front and contracted to the midrib which suddenly 
broadens out into a blade composed of 2 symmetrical halves that 
can fold together along the line of the contractile and irritable 
midrib region. Along the margin of each half of the blade are 
long, stiff, non-irritable bristles which, on closure of the blade, 
interlock with each other. On the center of the upper surface 
