I6 
WAYSIDE AND WOODLAND TREES. 
makes them very useful in boat-building, as “ knees ” of 
various angles may be cut from them without having recourse 
to bending. The best knees are to be obtained from Oaks 
grown in the hedgerow. 
The Oak flowers in April or May, and the blossoms are of 
two distinct forms — male and female. The males are in little 
clusters, which are borne at intervals along a hanging stalk, 
two or three inches in length. They are green, and therefore 
inconspicuous ; but examined separately, they will be found to 
have a definite calyx, whose margin is cut into an uncertain 
number (4 — 7) of lobes. There are no petals, but attached to 
the sides of the calyx there are ten stamens. The female 
flowers are fewer, and will be found on short erect stalks 
above the male catkins. Each female flower consists of a 
calyx, invested by a number of overlapping scales, and en- 
closing an ovary with three styles. The ovary is divided 
into three cells, each containing two seed-eggs. An acorn 
should therefore contain six kernels, but, as a rule, only one 
of the seed-eggs develops, though occasionally an acorn 
contains two kernels. The overlapping scales at the base 
of the female flower become the rough cup that holds the 
acorn. 
The Oak is subject to a considerable amount of variation, 
probably due to differences of situation, soil, etc., and some 
authors have sought to elevate certain of the varieties into 
species by giving them distinctive names. It does not appear 
to be certain, however, that these forms are at all constant, 
and they are connected by intermediate forms that make the 
identification of many individuals a matter of difficulty. In 
one of these forms {scssiliflora) the stalk of the acorns con- 
necting them with the branch is very short, but the leaves 
have a distinct footstalk, from half an inch to an inch long. 
This form is more plentiful in the north and west, and is 
conspicuous in the Forest of Dean. A second form, known 
