ANIMALS AND PLANTS 253 
ing the germination. The mountain laurel (Kalmia) 
of eastern America has the stamens in the freshly 
opened flower bent outward, and the anther fitted into 
a little pocket from which it is set free by an insect visit- 
ing the flower; the suddenly released stamens spring 
inward much as in the barberry and scatter their pollen 
in the same way. 
Among the sympetalous Dicotyledons the devices for 
effecting cross-pollination are often exceedingly perfect. 
Most of these have tubular and often two-lipped flowers 
which are very generally incapable of self-fertilization. 
The labiate flowers are usually horizontal or pendulous, 
and often adapted to special insects. Thus the common 
foxglove (Digitalis) is mainly visited by large bees, 
which creep into the bell-shaped corolla, where the back 
comes in contact with the open anthers which lie against 
the upper part of the corolla. Here the stamens mature 
first, so that ordinarily the pistil is pollinated by pollen 
from a younger flower, but it is said that in case insects 
are prevented from visiting the flower, self-fertilization 
“is possible. 
In various Labiate, or Mints, e.g. Lamium, Salvia 
(Fig. 57, A, B), the arrangements for cross-fertilization 
are very complete, and probably in both of these genera 
self-fertilization is impossible. In the former, while 
stamens and pistil mature about the same time, the 
stigma hangs below the stamens, and its receptive sur- 
face is turned away from them so that no pollen can 
fall on it from above, and a bee entering the flower, 
with pollen taken from another one, will touch the 
stigma and deposit the pollen upon it, before it comes 
in contact with the stamens. In the various species 
