BOTANICAL EVOLUTION. A7I 
to the south, self-fertilization has become the rule, probably on 
account of the paucity of insects, and in all such cases the flower 
heads have become so reduced in size and so inconspicuous, as to be 
almost undistinguishable except to the experienced eye. 
Finally, among some flowers, of which the Violets appear to 
possess the character most strongly developed, two kinds of flowers: 
are produced on the same plant; one of which is rendered specially 
attractive by its colour, perfume and nectar, and is especially 
contrived for insect fertilization. But of course it is always possible 
that insects, from some cause or another, may not visit the flowers, 
and as if to guard against this contingency, a set of self-fertilizable 
flowers are produced later on in the season. These cletstogamic 
flowers lack the parts which are developed in the others as attractions 
to insects, and in them everything is produced on the most econo- 
mical plan possible. The sepals are well developed, for they are 
required for covering organs; the petals are greatly reduced in size 
or are wanting altogether; of the stamens only one or two are fully 
developed and these have their anthers applied directly on to the 
stigma; while the pistil being the part most essential to the formation 
of the seed is fully formed. Then the stalk is very short so that the 
seed-vessel ripens close to the ground, and as it approaches maturity, 
the capsule buries itself so that the seeds are at once in a position to 
germinate. 
It must be quite evident to you from the scattered examples 
which I have adduced, that the one great object of securing the pro- 
pagation of their kind is attained by plants—as far as their stems, 
leaves and flowers are concerned, by very remarkable diversity of 
means. This is equally the casein the production of their fruit and 
seeds whereby the cycle of their individual existence is closed. The 
popular acceptation of the term “fruit” is something succulent, and 
usually eatable. The botanical sense of the term includes every part 
which is concerned in the ripening and distribution of the seed. It 
is indeed chiefly in the latter direction that modification has taken 
place. 
Systematic botanists, and those whose aim seemed to be to 
enumerate as many kinds of fruit as possible, used to divide fruits 
into about three, or sometimes four, classes. Thus all fruits formed 
from the pistil only, and which open to scatter their seeds, constituted 
one group. A second included those which do not open, but which 
liberate the seed by the decay of the wall, as in ordinary stone fruits 
and nuts. A third group was formed of those which consist of 
several carpels joined together, and which merely come apart when 
ripe, and which are termed schizocarps. To the fourth belonged a 
very heterogenous assemblage of fruits in which the pistil is always 
associated with some other part of the flower, and which are called 
pseudocarps. Of course for systematic work some short, cut-and-dry 
system of classification is more or less necessary, but it is always 
bound to be very artificial, as long as merely morphological features 
are taken into account. We may take a curious example from the 
fruit of one of our commoner heaths, Gaultheria antipoda. The calyx 
of the flower of this plant does not fall off when the petals wither, but 
remains as a protection to the fruit. Sometimes the calyx is green 
and leaf-like and the fruit dry, opening when ripe; this form is called 
