570 How the Pitcher Plant got its Leaves. [June, 
on one side by an upright hood (Fig. 3), the inner surface of 
which is thickly covered with short stiff hairs, all pointing down- 
wards. The interior surface at the bottom of the hollow is lined 
with slender bristles (Fig. 4). These extend about one-third of 
4.—Hairs of Sarracenia pur- 
Fic. 
purea,; b, base; a, top. 
over the first one. The hollow is more 
complete ; the hood is 
conspicuous and attractive; the smooth 
surface at the center of the hollow is a 
more effectual safeguard against the es- 
cape of insects, and the 
way better adapted to secure insect prey. 
Still the pitcher is open to the rain, se- 
cretes little or no nectar, and absorbs the 
juices of the insects it captures in the form 
of a liquid manure only. 
The next step in advance is found in a 
southern species of the genus with larger 
and more upright leaves, known as Sar- 
vacenia flava. The arrangement of the 
hairs in the interior of the leaf is the same : 
but a saccharine secretion just below the 
hood shows a marked difference, and is a 
more effectual lure to insects than merely 
a colored surface such as there is in the 
the way up. Then comes a per- 
fectly smooth, glaucous surface, 
extending another third of the 
way, and above it is another set 
of hairs similar to those on the 
hood. In this leaf there is a 
marked advance in development 
larger and more 
plant is in every 
bs 
Sp ecies previously referred to. _ The pro- Fic. 5.—Leaf of Sarracenia 
Mee visions for the retention of insects are 77#olaris. 
=~ equally good in both species, but in the flava a secretion of honey 
acts as a bait. It seems 
to possess, too, a slight trace of a delete- 
