458 JOURNAL OF SCIENCE. 
their stamens become transformed into petals, as in the rose, poppy, 
&e., the two anther-lobes do net stand close to one another, but are 
frequently separated by a tolerably broad piece of leaf, which is the 
expanded connective. This is the view adopted by Sachs and Hugo 
- y. Mohl, but the common morphological interpretation is that the 
filament represents the petiole or leaf-stalk, while the anther-lobes 
represent the swollen halves of the leaf-blade. For either view of 
the question numerous arguments could be advanced, but for our 
present purpose -it is enough to know that the stamen as a whole is 
definitely accepted by botanists as a modified leaf. 
The most important part of the stamen is the pollen, which is 
the fertilismg element of the flower. I will not take take time to 
trace the origin of pollen, to do which would require a detailed 
examination and comparison of the corresponding organs in the 
lower families of plants. It must suffice to state that such an 
examination and comparison would show that a marked similarity 
exists among the male organs of the higher flowerless plants and all 
flowering plants, and that this similarity adds to the already strong 
evidence for the common origin of these two apparently widely 
separated groups. Pollen granules are most usually of a bright 
yellow colour, and it is of importance to remember this fact as I 
hope to show later on. More rarely it is found of a whitish, orange 
or greenish colour, while in one genus very familiar to us, viz., 
Fuchsia, it is of a bright blue colour. But this is evidently the result 
of considerable differentiation. F 
To understand the function of pollen, we must next consider the 
organs which occupy the central position in the strawberry, the pistil 
or carpels. The term pistil is applied to the whole assemblage of 
them, and each carpel consists of an inflated portion or ovary, con- 
taining a single ovule or rudimentary seed. On the summit of this 
is a small stalk or style, and a small expanded viscid portion or 
stigma to crown all. The object of the viscidity of the stigma is to 
enable it to catch and retain pollen grains. When a grain of pollen 
adheres to a stigma, it emits a tube of extremely delicate structure, 
which grows down through the style into the cavity of the ovary, 
and enters the ovule, fertilizing it. After the act of fertilization 
has been thus accomplished the ovule undergoes great develop- 
ment, and in due course matures into a seed. The whole question of 
the evolution of the flower hinges on this process of fertilization, and 
all the marvellous modifications of floral structure with which we are 
now familiar have originated and have been carried on with the 
object of accomplishing this process in the most perfect manner. 
But still to come back to our strawberry, we find outside the. 
stamens a ring of five white leaves or petals. These partly serve to 
protect the internal parts, but their principal function—at least in 
this plant—is to render the flowers conspicuous to insects, which have 
a very important connection with many flowers, and are, indeed, 
essential to their reproduction. Outside of the petals are five green 
leaves or sepals, and a second row of five bracts, but these ten are 
so closely united as to make a single calyx of ten leaves. Bracts and 
sepals, however much they may be modified in ordinary flowers, are 
evidently derived by modification from ordinary foliage leaves, and 
serve almost exclusively as covering organs. Petals on the other hand 
