7 2 THOMPSON YATES LABORATORIES REPORT 
mosquito a similar worm of the same size was found. A living mosquito was then 
taken, quickly killed by chloroform, and without any dissection whatever the thorax 
was pierced by a needle, and the finger nail placed on the tip of the proboscis. The parts 
were then gently drawn apart, the labium and palpi being thus separated from the 
stylets. A very active filaria was then seen to curl itself out from the neighbourhood of 
the trachea of the labium. This lived for about an hour in normal saline, coiling and 
uncoiling itself. The other two Anopheles died during the following night and on 
dissection proved to be negative. 
In this stage, the seventh, the worm according to our specimen, is about 
i "006 mm. long and 0*025 mm - broad. It tapers slightly to each end. At the 
anterior end, which is rounded off, the cuticle is thickened in places to form a few 
very small papillae disposed around the oral orifice, which is terminal. The posterior 
end, which is also rounded off, is provided with four papillae which are almost at 
right angles to the axis of the body of the worm. The position of the anal orifice 
cannot be definitely decided. . The alimentary canal can be seen to run straight 
down the worm and shows no differentiation as far as we have been able to ascertain 
in oesophagus and intestine. Besides the alimentary tube in parts two other 
tubes can be seen which are for the most part straight, but at one or two points 
seem to twist round the intestine. Towards the head end at a distance of 0*14 mm. 
from the anterior end, there is an indication of the presence of an orifice towards 
which the reproductive tube is seen to bend. 
Filariae in Anopheles costalis 
According to our notes 281 Anopheles were examined for filariae — -sixteen of 
these (5*7 per cent.) were found to contain the worms. The following are the 
details of the examinations : — 
1. Two large filariae. 
2. Eight to ten among thoracic muscles. 
3. Several young larvae. 
4. About ten large forms in thorax. 
5. Several large forms among the thoracic muscles. 
6. A single large filaria. 
7. A small larva dissected out from the head. 
8. Eight small larvae in thorax. 
9. A few young forms in thorax. 
10. Four young larvae. 
1 1. Ten larvae found. 
1 2 . Fourteen larvae in thorax. 
13. Several large larvae. 
14. A single larva. 
15. A single large larva found at the base of the proboscis. 
16. Ten filariae in thorax. 
