1883. ] Means of Plant Dispersion: 1031 
droppings. In this manner raspberries, blackberries, strawber- 
ries, the elder (Sambucus), poke (Phytolacca) and many others, 
which furnish food to birds, are multiplied. 
It is therefore evident that the larger edible fruits, with their 
rich pulpy sarcocarp and much smaller volume of seed, do not 
exist alone for the animals that feed on them, but have another 
end to serve, the preservation of their kind. The more attractive 
the more likely to gain in the struggle for existence. If the 
color, form, odor, or any other peculiarity of a flower be ex- 
plained on the principle that its end is the advantage of the 
plant bearing it, so we are to consider our various fruits as largely 
subject to the same law. There is mutual adaptation in the two 
kingdoms of nature, proceeding from its wise Author, but so far 
as the plant and animal are concerned, they are governed by a 
selfish principle, the law of self-preservation. The beauty we 
admire in the scarlet aril enclosing the seeds of the wax-work 
(Celastrus) and waahoo (Euonymus) when the pod opens to dis- 
play them in the fall; the redness of the berries of the elder 
(Sambucus pudens), and of the mountain ash (Pyrus americana), 
are so many signals held out to attract the eye of the passing 
bird, inviting it to come and eat, however much they may con- 
tribute to the enjoyment of the eye that dwells upon their color. 
IV. Another contrivance for spreading seed is the elastic move- 
ment of the coats of the seed-vessel at the time of maturity. 
Some of the best and most familiar examples are in the geranium 
family, The two wild species of Impatiens (/. fulva and J/. pal- 
lida) are excellent cases of this kind. The walls of the ripened 
pods, still considerably succulent, suddenly contract and roll to- 
gether, especially if some external stimulus be applied, as a touch 
or the action of the wind, and throw the seed outward to some 
distance from the plant. The wild species are exceedingly sensi- 
tive, opening so suddenly and at so slight a touch as to be almost 
startling in its unexpectedness, and hence have acquired their com- 
mon name, touch-me-not. The wild geraniums possess this prop- 
erty, but to a less marked degree. The receptacle of the flower is 
Prolonged into a slender beak, around which, at the base, the five 
cells of the capsule are arranged. Each cell tapers upward into 
a slender prolongation formed by the hardened style, and adheres 
to the beak at the top. When ripe they break away from the 
base, curl. upward so as to bring the inside of the cell outward, 
