50 NOTES ON A MALARIA -CARKYING MOSQUITO 



traced parts of the insect. The head, with its orj^an-, wings and 

 long legs are very neatly packed up inside. To .show how these 

 spiracles are situated, I have a view of the gentleman's back, 

 taken as he floats on the water. He was alive, and had the good 

 manners to remain still on the stage of the microscope while he 

 was having his portrait taken. In the succeeding view (Fig. 7), 

 is one of the spiracles detached. It differs in shape from the 

 organ of the ordinary Culex, so that the pupa may be dis- 

 tinguished by this feature alone. In the Culex it has a 

 resemblance to the leg of a Wellington boot with the top cut off 

 transversely. In the Anopheles it is shorter and open for the 

 most part of its length. It is not unlike the coal scoop seen in 

 the parlour coal boxes in the old country. Before leaving I will 

 show you the powerful swimming apparatus attached to his 

 latter end. Being almost transparent, it does not photograph 

 well, so this is taken on a dark ground, and brings the outlines 

 very distinctly before you. The next object is a live cell with a 

 number of the pupa disporting themselves in the water. You 

 see the way in which the tail fans strike the water backwards, 

 the rebound projecting the insect through the water as though it 

 were a football driven by a powerful kick. 



The succeeding picture (Fig. 8) shows the final stage being 

 completed. Here the insect has been matured in the pupa case. 

 This may occupy three days in summer or a fortnight in winter. 

 It has been preparing for a change of life, and has seemed 

 conscious of some impending change, for it manifests a general 

 uneasiness, darting through the water with quick, jerky move- 

 ments. Then, if carefully watched, the skin at the back of the 

 head is seen to split ; then the mosquito's head appears. Slowly 

 the slit enlarges, and the shoulders and chest appear. No 

 decided motion is traceable for a while, but still there is progress. 

 Now the insect bends forwards, releasing a little of the wings 

 and body ; then bending backwards a little more of the legs is 

 freed. So this alternate movement continues until the forelegs 

 are free. These are then placed on anything near, and by the 

 leverage they give the rest of the body is soon cleared. "When 

 the wings have been outstretched a few times they are put to 

 their intended use, and bear the insect away to new fields and 

 pastures green. In this figure the insect has succeeded in dis- 

 engaging itself with the exception of the tips of its long legs, 

 which are entangled in the pupa case. When once free the 

 Anopheles are easily distinguished from the common variety. 

 Here is one of the common kind (Fig. 10). It was photographed 



