THE EGGS OF SOME BRITISH BUTTERFLIES 31
purposes. Of the hemlocks, Western Hemlock (Tsuga hetero-
phylla (Raf.) Sarg.) from western North America, yields a
serviceable wood for constructional work, although it is probably
a less desirable timber than that of Douglas fir. Of the wood
derived from the Eastern Hemlock (T. canadensis (L.) Carr.)
the less said the better.
Only one representative of the conifers of the Southern
hemisphere is seen commonly in Britain, the Chili Pine or Monkey
Puzzle (Araucaria araucana (Mol.) K. Koch). This tree produces
a tough yellowish white wood which is put to much the same uses
in Chili as is Scots pine in Europe; but in Britain it is scarcely
likely to prove a serious competitor to red deal.
With the present fuel shortage it is perhaps appropriate to
mention softwood timber as a source of fuel. Many coniferous
woods burn well, with an intense heat, but they are rapidly
consumed and, moreover, some tend to throw out sparks and
must be constantly watched. On the whole softwood logs are
best avoided, but an exception must be made of yew, which is
one of the finest firewood timbers which grow in this country.
BIBLIOGRAPHY
Boulton, E. H. B. and Jay, B. A. 1946. British Timbers. London.
Dallimore, W. and Jackson, A. B. 1931. Handbook of the Coniferae.
London.
D.S.I.R. (Forest Products Research). 1945. Handbook of Empire Timbers.
London.
--------------------------. 1941. Handbook of Home-Grown Timbers. London.
Hyde, H. A. 1935. Welsh Timber Trees. Cardiff.
THE EGGS OF SOME BRITISH BUTTERFLIES
BY E. E. SYMS, F.R.E.S.
[Read 30th November, 1946]
THE study of the eggs of insects is a fascinating one, although
their small size makes the use of a lens necessary to see their
shape and markings. The eggs of the butterflies are often of
beautiful shapes and the markings are more elaborate than those
of the eggs of other insects.
In order to understand how these markings are produced it
is necessary to examine the internal reproductive organs of the
female. These consist of a pair of ovaries, two lateral oviducts
which converge from the ovaries, and a median oviduct which
receives the lateral oviducts anteriorly and opens posteriorly to