The following notes were suggested by “Observations,” &c" on Aphides in The Canadian Entomologist for July, 1873. The species noticed on Rumex crispus seems to have very much resemblance to A rumicis of Europe; some other species of N. America do not differ from those of Europe, but have been probably introduced by means of shipping. With regard to European Aphides it is well known that the winged female of many species appears in the spring, that the wingless female is more fertile than the winged one, that the winged state is, partly at least, by means of the diminution of quantity or alteration of quality in the food, and that the winged state enables the species to have a change of habitation and thus to continue its race till the autumn.