196 DR. S. H. LONG ON THE MOSQUITO-MALARIA THEORY 
you. It was at one time asserted that A. maculipennis could be 
distinguished at a glance by the fact that when resting on a 
vertical surface, such as a wall or mosquito curtain, it sits with its 
body forming an angle of about 30 degrees to the surface, whereas 
with the other varieties of the Anopheles and the Culex this angle 
between the body and the supporting surface is one of 70 or 
80 degrees. I mention this, and show diagrams to represent more 
exactly my meaning, because it has been stated in many papers 
that this characteristic can be used as a means of distinguishing 
this species generally ; whereas it has since been pointed out by 
Dr. Sambon that it holds good only for the species of a certain 
locality, the West African coast. 
* With regard to the Life History of the Anopheles, time will not 
permit of my entering into this. I here show you some beautiful 
drawings by Drs. Nuttall and Shipley, kindly sent to me by one 
of the authors, which show the evolutionary changes that take 
place from the egg through the pupa stage to the imago or perfect 
insect. The female Anopheles lays about one hundred eggs, and 
these are deposited upon the surface of water containing suitable 
material, such as Algae, as food for the larvae. On the second or 
third day the larva leaves the egg. As far as the evidence at 
present goes, it would appear that the eggs are non-resisting to 
hibernation, and can only be carried through the winter in the 
body of the female Mosquito. The larva of Anopheles moves in 
the water tail first, and it lies with its body parallel with the 
surface, whilst the body of Culex hangs nearly at right-angles 
to the surface. By this means the larva of Anopheles can be 
distinguished from that of Culex. Anopheles larvae are nearly 
always found in clear water, whereas that of the Culex does not 
appear to find sufficient food in water of this kind. The larval 
period lasts from eighteen to twenty-one days, the length of time 
depending considerably upon the temperature. The pupa develops 
into the imago in from two to three days. 
With regard to the habits of Anopheles, there are some here this 
evening who could probably give many facts from their experience 
of these unwelcome insects so often met with during the summer 
months on the rivers and broads of this county. Anopheles 
maculipennis seems to be quite the most domesticated of the 
species. During the day they remain hidden and sheltered in 
