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4 



The difteirenees aife well exemplified 

 in the lantern Blides, which I will 

 now show you, and they extend 

 through the insects' hves from begioniog 

 to end. In the first place they may be 

 readily enough distinguished by the 

 attitude assumed in resting. Anopheles 

 seems always to be endeavoring to stand 

 on its head, while Culex rests parallel 

 with the surface in a hunched up position. 

 This, of course, is a rough test, but after 

 a little while one becomes very expert in 

 distinguishing the two in a locality 

 where Anopheles are present. I may 

 state that I do not know that any species 

 of Anopheles existing in Tasmania, al- 

 though one species has been recently 

 described as existing in Victoria. I 

 have not come across a member of the 

 genus in a large number of mosquitoes 

 lately examined in Tasmania. All species 

 of Anopheles are not capable of conveying 

 malaria, a fact which explains the 

 presence of this genus in non- malarial 

 localities where cases are from time to 

 time introduced. The female, by the 

 way, is usually the blood-sucker amongst 

 mosquitoes, a meal of blood being stated 

 to be essential for the fertilisation of the 

 eggs. The male, except in the stegomyia 

 and a few others, is an innocent creature, 

 preferring a vegetable diet of fruit juices, 

 if indeed he does feed at all, and not, like 

 his partner, varying it with animal food 

 extracted in a voracious and annoying 

 manner. 



Both male and female are here shown, 

 but, taking the latter first, you will note 

 the length of the palpi — as long or 

 longer than the proboscis. This is in 

 itself, in the female, a mark of the 

 genus. The wings are spotted in both 

 specimens — another fair but not infallible 

 guide-mark to the Anopheles. Turn- 

 ing to the male, you will note that the 

 palpi are also long, but they are always 

 long in the male, whether of Anopheles 

 or Culex. These, however, are clubbed 

 at the ends, and in this particular species 

 are plumose at the ends. The dis- 

 tinguishing marks of the male in this 

 case, as in others, are the large plumose 

 antennae — regular whiskers, as befits the 

 sex. The adult msects can thus be dis 

 tinguished, but for complete identification 

 this is not enough. Various markings of 

 the legs and palpi, and the arrangement 

 of the wing and body Bcales, are used to 



identify species. The shape of the eggs 

 is different in the two genera, those of the 

 Anopheles possessing a distinct boat shape, 

 while Culex eggs are blunter for the most 

 part. They are laid in masses of from 200 

 to 400. These eggs develop in the course 

 of from 12 hours to several days into larvae, 

 which are known to every boy as the 

 "wigglers," found in every tank and pool 

 in fairly warm weather. Here we note 

 another difference in the genera, the 

 Anopheles lying parallel with the surface 

 owing to the absence of the long breathing 

 tube, which enables Culex to hang down 

 from the surface — the direct opposite of 

 the position assumed by ihe adult insects, 

 as you will recollect. The arrangement 

 of the hairs upon the different segments 

 enables species to be determined. In a 

 week for Culices or more for Anopheles — 

 the time varies considerably in these pro- 

 cesses for different species and under 

 different conditions — the active wiggling 

 larva after develops into a pupa, which 

 again differs in the two genera, and after 

 a varying period of from two to 10 or 

 more days the pupa case splits down the 

 back, the adult insect emerges, and after 

 balancing itself on the empty case for a 

 while in order to dry its wings, flies away 

 to propagate its kind in turn. 



To sum up the points which I have 

 endeavored to briefly indicate we have 

 the following facts to consider wherever 

 malaria is to be dealt with. There is 

 firstly a blood parasite, which is the 

 cause of the disease, and next come 

 particular species of a particular genus 

 of mosquito, whose tissues afford 

 the only place wherein this parasite 

 can complete its life cycle. Malaria can 

 be conveyed from man to man by inject- 

 ing blood in which the organism 

 is, but this need not be considered in 

 practice. Therefore, in tackling the ques- 

 tion of stamping out malaria we naturally 

 attack the mosquito. The adult 

 insect may he guarded against by mos- 

 quito curtains and other measures to 

 prevent its biting — a particularly useful 

 one by the way consists in wearing two 

 pairs of socks after dark, a thick paii 

 underneath and a thin pair on top, 

 since more people are perhaps infected 

 at the dining tabic than in almost any 

 other way, the Anopheles loving the 

 dark lurking-places under ihat cheerful 

 board. It may also be killed by 



