The common method of killing mosquito larvae with hot water followed by the usual steps in dehydration causes so much distortion and the loss of hairs that it interferes with the identification and complete description of the larvae. It occurred to the writer that the method of killing was too drastic. The technique to be described should be carried out in a series of small preparation dishes or watch glasses. The steps are itemized as follows:
1.Place the larvae in 1.5 per cent magnesium sulphate solution for fifteen to twenty minutes. This will clear the specimen of foreign matter.
2.Place in clear water for two or three minutes.
3.Transfer to 2 per cent cocaine hydrochloride solution (1) until they are dead. The siphonate larvae require four hours the asiphonate larvae two hours in this solution before it kills them. The results, however, more than repay for the time consumed.