BACOT : MOSQUITOES AND THE DANGER OF MALARIA.
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plane of the body; while, in Anopheles, the direction of the
proboscis is in the same line as the rest of the body.
Some species of Culex feed by day, others by night. Anopheles
mosquitoes almost invariably feed at night only, unless dis-
turbed by day.
The breeding grounds of the two groups are very generally
distinct, although, as might be expected, some overlapping
occurs ; the species of either group with the more generalized
habits being found in situations which are favourable to both,
though possibly, even in these cases, it is strictly rather a question
of sequence, the character of the pools altering, owing to changes
in weather, more quickly than the development of the larvae
proceeds.
Larvae of Anopheles are usually found in open water favour-
able to the growth of algae or other organisms tolerant of sun-
light. Larvae of Culicina are more frequently present in
shaded pools of turgid or foul water, often in very small im-
permanent pools or domestic collections of water wherein the
micro-organisms are likely to consist of bacteria or yeasts,
rather than algae.
The larvae of some species, such as the yellow fever mosquito,
seem to flourish best in situations which necessitate quick hatch-
ing and speedy development ere the small quantity of water
present evaporates. Freedom from competition and enemies
are, seemingly, of greater importance to these species than the
risks of total mortality from drought.
IV.—THE PRESENCE OF "AGUE" (OR MALARIA) IN ENGLAND.
In the past, Ague was a widespread and a very real scourge
in England. While confined chiefly to the Eastern and South
Eastern counties, it extended in more or less isolated centres
far to the North and, during the eighteenth century, was
prevalent on the borders of Scotland. There is no evidence
that it ever invaded Wales ; but, although Ireland had the
reputation of being free from Ague, writers speak of epidemics
in Dublin in 1805 and again in 1829. On this last occasion, it
was supposed to have been imported from the English fens.
It is stated that, in the past, England lost from this disease
two Kings, a Queen, a Cardinal, and a Lord Protector, as