1885. | How the Pitcher Plant got its Leaves. 569 
secreting or absorbing hairs, but serve simply to prevent the 
. escape of insects which have once found their way inside. This 
may be regarded as the nearest living equivalent of the original 
and ancestral form, but even it has, of course, been greatly modi- 
fied to suit altered conditions. 
> 
Fic. 3.—Leaf of Sarracenia purpurea. 
Next in order, but a little more modified, comes the widely 
dispersed Side-saddle flower (Sarracenia purpurea) of the bogs of 
the Eastern and Northern United States. In this species the leaf 
forms a more perfect tube, open only at the top, and surmounted 
