Geraniums 35 
(J. noli-me-tangere), with red-spotted flowers of pale- 
yellow hue. The stamens in this species mature 
before the pistil to favour cross- 
fertilisation, for which the position of 
the organs is admirably adapted, for 
a bee entering the roomy sepal cham- 
ber must dust its back with pollen, 
and on visiting a somewhat older 
flower must pollinate the stigma. Yet 
the arrangement has not attained to that high degree 
of specialisation which would absolutely prevent self- 
fertilisation, for though Mr. Darwin covered up some 
flowers with fine net to exclude insects, eleven of 
them produced seed-capsules with a few good seeds 
in each. 
The handsome Jewel-weed, or Snap-weed (J. fulva), 
that has made its way from North America and 
settled along many of our streams, has orange flowers, 
with the spur abruptly curved under the sepal sae. 
This is said to be so highly specialised for cross- 
fertilisation that even when artificially pollinated 
the pollen has no effect on the stigma of the flower 
that produced it. But to guard against the accidents 
to which such highly specialised flowers are subject, 
both these species produce minute cleistogene flowers, 
like those of the Violet and the Wood Sorrel. 
Like the other branches of the Geranium family, 
Impatiens produces seed-capsules of 
the spring-gun order, and it is to 
these startling contrivances that the 
names Touch-me-not and Snap-weed 
are due. The seeds are attached to 
a central axis, and the five valves of the capsule are 
Section of Impatiens 
flower 
Seed-vessel of Impatiens 
