40 



CHAPTER III. 



The Anatomy of the Larva. 



From a purely anatomical point of view a good deal has 

 been written on this subject, but on the descriptive side 

 comparatively little has been recorded, so that except in 

 the case of a few of the commonest species, we are quite 

 without adequate descriptions whereby Gulex larvae may 

 be distinguished among themselves. In by far the greater 

 number of recorded species the larvae have never been 

 recognised, and still less described. It is obvious, however, 

 that as these insects can be much more easily destroyed in 

 large numbers in the larval stage, by insecticides, or by 

 the filling up of pools, than they can be as Hying insects, 

 the accurate description of the larvae of noxious species 

 has become a matter of great importance ; but it is un- 

 fortunately one that can, as yet, be hardly said to be 

 commenced. 



Observations on this subject, by " breeding out " adult 

 insects from larvae, require much time, and, above all, a 

 settled residence, and the work of the Sanitary Com- 

 missioner of an Indian province is of a kind that precludes 

 either requirement, so that my present visit to India has 

 been very unfruitful in results in this direction, and I still 

 can only offer a few general suggestions for future work. 



As regards the genus Cidex, I believe that the pro- 

 portional length of the breathing tube, as compared with 

 that of some comparatively fixed portion of the body, such 

 as the head or thorax, will be found to yield valuable specific 

 characters. 



I was at first inclined to think that this proportion 

 varied greatly with the age of the larvae, but found subse- 



