1. There appears to be a general similarity in the tastes of the different species with regard to various chemicals and foods; the tastes of Musca domestica and Phormia azurea, in many cases, being found to approximate most nearly. It will be interesting to discover whether there is a closer correspondence between the sense-organs of these flies than between these of other species.
2. These experiments emphasise the extreme curiosity of house-flies, and again show the catholicity of their tastes and the difficulty of finding any substances which will either attract or repel all those that come near it. The mineral and tar oils seem to be amongst the most repellent substances. With regard to poisons, good results were obtained with sodium iodate, large numbers being killed when very small amounts were used, although it did not always attract many flies. Sodium iodate has the disadvantage of being very expensive. But further experiments require to be made before any definite conclusions can be arrived at as to the importance of the iodates of sodium and other metals as poisons for general use.
3. House-flies were not found to show any colour-preference.
4. For house-flies the optimum temperature was found to be between 36°–44° C., the maximum and minimum between 55°–58° C. and 10°–13° C., respectively.
5. It appears that curiosity plays an important part in causing house-flies to come to baits and to investigate traps, etc., although the senses of smell and to a less extent that of sight are also concerned; the former, however, to a much less extent than it is with blow-flies, and it appears to be most used when the flies are close to the baits.