It is noteworthy that the breeding-places of different mosquitos vary with the seasons and that mosquitos are influenced in the selection of their breeding-places by such differences as those of temperature, relative humidity, cloudiness and rain, or alkalinity and food supply, and a further study of the breeding-places of Aëdes (Finlaya) notoscriptus, Skuse, has revealed some interesting details worthy of record. In this respect the importance of continuous mosquito work becomes particularly apparent, because at times the results obtained seem almost to be of a contradictory nature; but these variations are due to the diverse conditions under which mosquitos are forced to live in a country which at one time is subject to excessive rains and at another in the throes of a great drought. These factors tend to give to certain mosquitos an economic significance, and therefore we must not be surprised to find a semi-domestic species like A. notoscriptus displaying at times a tendency to become domestic; this mosquito has already taken to breeding in water-tanks in Western Australia, and fears of its doing so in Brisbane, when its present breeding-places have been largely done away with, seem justified.