BACOT : MOSQUITOES AND THE DANGER OF MALARIA. 257
a service being inaugurated before the men return from overseas.
Sufferers from malaria will have relapses of fever without the
use of either mosquito curtains or the administration of
quinine ; for the local doctor will probably have no information
when a potential malarial patient has moved into his district.
Two cases of malaria in persons who have acquired the
disease, though they have never been out of the country,
have already been recorded in the medical papers. This is the
reason why the Local Government Board is turning towards
the last line of defence—the control of Anopheles mosquitoes.
We have in England three species of Anopheles mosquitoes :—
A. maculipennis (figs, 2 and 3, Pl. v.), the commonest carrier
of the disease in Europe ; A. bifurcatus, a less common, but
implicated, species: and A. nigripes. This latter was con-
sidered formerly to be rare, but Edwards has discovered
a species breeding in water holes in the roots of beech
trees, which he identifies with a species that Christophers
records as common in root holes of trees at Simla in India.
Christophers identifies his species as Anopheles plumbeus, but
further states that it agrees in all respects with the specimens
of A. nigripes at Cambridge. Our third English species of
Anopheles appears, therefore, to be Anopheles plumbeus, while
its supposed rarity is probably due to its restricted and (for
an Anopheles mosquito) unusual habitat. It occurs in Epping
Forest, where I took a larva this autumn from a hole in a beech
tree in Monk Wood (fig. 10, Pl. vii.), with larvae of a species of
Ochlerotatus, probably 0. geniculatus. There is no evidence that
this species is able to convey malaria ; and we shall probably be
safe in considering that, for all practical purposes, Anopheles
maculipennis is, with us, the important species of mosquito to
control. This is fortunate for the Epping Forest authorities, as
it is impossible to estimate how many water holes are present
or in process of formation, not in the roots only, but in the
boles of the trees, owing to the neglect of the use of the
hand-saw and tar-pot. except where sweeping branches interfere
with horse traffic. Elsewhere, broken boughs and projecting
snags rotting back into the trunks may be seen by the thousand.
The evidence recently asked for by the Local Government
Board will be of service at present only in so far as it will enable
them to chart the Anopheles-free districts, because we possess