346 
POPULAR SCIENCE REVIEW. 
flowers. Eacli little tiny flower growing in the round white head 
is a perfect type of the order to which it belongs, and possesses 
all the characteristics which we have described in the Legurni- 
nosae. There is the tiny calyx, with ten little markings or 
ribs on its surface, and cut into five small teeth at the 
top, two of which are longer than the others. This con- 
tains the corolla, with its curiously-shaped parts ; the two 
side petals or wings, the protruded keel in front, and the 
standard or erect petal at the back (fig. 3). This is some- 
times marked and striped with a pinkish colour. The keel 
incloses the ten stamens (fig. 4), nine together and one 
alone ; and the style, which becomes in time the legume, 
or the pod (fig. 5), containing the little seeds (fig. 6). Very fre- 
quently we may notice as the season advances that the white 
heads of the clover are fringed round with dead or withered 
flowers, which lose their upright position and hang down level 
with the stalk. These are the flowers which have performed 
their function : they have matured the provision for future life 
within themselves, and contain the tiny pod, with its two or 
three seeds which will perpetuate their species. Contrary to 
the general law in plants, the petals do not fall off when they 
wither and the fruit is formed, but remain persistently on the 
flower-stalk and calyx until the whole plant perishes. The 
outer row of flowers, coming first to perfection, fall downwards 
and form this brown fringe-like appearance round the head. 
Having carefully examined every part of the flowers, let us 
. take a leaf with its thin delicate stalk, and observe the beautiful 
markings on its surface, and the crescent-shaped figure which 
is impressed towards its base — sometimes hardly perceptible, at 
others of a darkish purplish colour, and very distinct. This 
coloured marking of the leaf sometimes extends over its whole 
surface, and clover leaves are often found in which the green 
colouring matter, or chlorophyle, has entirely assumed a purple 
hue. This change suggests to us that it is by no means essen- 
tial to the nature of a leaf that it should be green. In the 
varied and beautiful tints of autumn, who has not been struck 
with the almost gorgeous colours of leaves ? Bright red, 
brilliant orange, and deep purple, vie with each other to com- 
pensate to the eye for the absence of summer flowers. And in 
these very flowers, whose coloured petals at first sight seem 
altogether different from the surrounding leaves, we may 
shortly be able to trace evidences of identity with the green 
forest around them. 
Let us now place one of the three little leaflets under the 
microscope. The markings are very distinct, and the edges of 
the leaf which appear so even and smooth to the naked eye are 
seen to be surrounded with points, towards each of which a 
