Vol. II., No. 10, JULY, 1885.1 
BOTANICAL EVOLUTION,* 
III.—FLowers anv Frutr. 
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In dealing with the subject of evolution of the flower, I shall 
only endeavour to show you certain general features of the origin of 
the flowers of ordinary Angiosperms, 7.c. those plants which have 
their seeds enclosed in an ovary or seed-vessel. In the first place 
if we examine an ordinary fir-tree, such as Scotch Fir, when in 
flower, we find that there are two distinct sets of floral organs. Of 
these sets one kind which we may term catkins, are composed of 
_closely-crowded thin scales covering numerous little stamens which 
when shaken emit great quantities of a light yellow-coloured powder 
or dust, called pollen grains. The other flowers are arranged in 
cones, and if we pull a young cone to pieces we find it also composed 
of crowded scales, but instead of being thin, they are thick and 
woody, and hidden under each lies a single naked ovule or seed. 
Now flowers are the reproductive organs of plants, and these two 
kinds may be said to represent the sexes, the stamens containing the 
male and the ovules the female elements. So in the Scotch fir, the 
male and female flowers are separately produced.’ Now to under- 
stand the structure of a flower and the origin of its parts, it is 
necessary to remember that the stamens andthe pistil (i.e. the 
portion containing the ovules) are the two essential parts; they are 
the parts chiefly concerned in the production of the seed which is 
the ultimate cause of the very existence of the flower, and therefore 
every other part must be looked upon only in the light of an auxiliary 
or secondary organ. 
It will, perhaps, just simplify matters if I ask you again to refer 
to the structure of a simple flower. Take, for example, the straw- 
berry. Here you have on the outside ten green leaves; the outer 
five may be considered as bracts, and the inner five as sepals. Then 
come five white petals; then a large number of stamens arranged in 
a ring, and inside of all a number of scparate pistils or carpels, small 
and greenish. In each carpel is one ovule, which when mature will 
form a seed. 
Now taking the important organs first. We find each stamen 
consists of a stalk or filament bearing on its upper end a two-lobed 
head or anther. In some cases this anther has opened by a longi- 
tudinal slit, and emitted a little mass of yellow granules, the pollen- 
grains. Now what are stamens? Judging chiefly by their position, 
their origin, the mode in which they develope, and lastly by the 
frequency with which they assume the nature of petals or even of 
ordinary foliage leaves, we reply modified leaves. The filament and 
the connective, i.¢., the portion lying betwecn the anther-lobes, 
represent the leaf, while the lobes themselves are apparently 
appendages. And this explanation of their structure is borne out 
by the fact that when certain flowers commence to double, z.e., when 
Tne eee 
*Continued from p. 421. 
