MALARIA, MOSQUITOES AND THE ESSEX MARSHES 39
were found. Outside this period, only females were found. He
also concluded that the unfertilised wintering female was the ex-
ception.
Because this species is present in small or large numbers
throughout the country, there is always the danger that fresh
cases of malaria may occur if an infective person comes into such
an area and is exposed to their bites. Fortunately, it is only
during the summer months that the temperature is such as to
allow of the completion of the parasitic cycle in the mosquito. The
conditions of favourable temperature and humidity occur most
commonly along the south and south-east parts of the country,
usually on the coasts, which is where locally contracted malaria
has been most commonly recorded. In many other parts of
England, although the mosquito is present and human carriers
have been introduced, the disease has rarely spread, unless warm
weather combined with a high relative humidity (over 60%), has
continued for some time.
In the British Museum publication, British Blood-sucking
Flies, one of the lesser-known but most interesting facts regarding
A. maculipennis is recorded. This species is one of four in the
domestic species group, i.e., those hibernating in buildings. These
differ markedly, not only in their external appearance but also
in their 'piping' when in flight. The female A. maculipennis in
flight produces a note which varies in pitch from middle C to
E. flat, according to whether the insect has fed or not. The note
of the male is much higher.
So much for the disease itself and the way in which it is
carried. Now let us follow the incidence of malaria in the past.
For a brief review of the early history of malaria in this country
to the middle of the 17th century, I am indebted to Dr. W. D. L.
Smith's report, 'Malaria and the Thames', and Creighton's classic,
'A History of Epidemics in Britain'. This early history is not
easy to trace with any certainty. Documentary evidence is not
only scanty, it is also suspect because one is not certain whether
the terms used for certain ills do, in fact, refer to what we now
call malaria. The Venerable Bede refers to a prevalent, long-
continued fever, translated as 'spring ill' which the Anglo-Saxons
knew as 'lencten adl'—'lencten' being the Anglo-Saxon for Lent.
He also mentions that St. Chad chose as the scenes of his ministry
two pestilential spots in Essex—Tilbury and Ithancester, near
Bradwell. Ague, or acute fever, in all early records may well have
referred to typhus or influenza or other fevers. Even as late as
the First World War, cases (later diagnosed as malaria) were sent
from Gallipoli provisionally labelled as typhoid and paratyphoid
and sometimes even as influenza and rheumatism. Malaria may
simulate almost any acute or subacute fever, and may be called
on this account 'The Great Mimic' amongst diseases. Some
authorities (including The Oxford English Dictionary) accept
Chaucer's 'ague' as malaria in his phrase, "Ye schul have a fever