AN article by A. S. Le Souef in the Journal of the Society for the presentation of the Fauna of the Empire shows how the impact of civilization has altered the fauna of Australia. Over the last 150 years, introduced mammals like the fox, rabbit, hare, cat, pig, black rat and common mouse have spread through the bushlands and are rapidly ousting the native marsupials and terrestrial birds. Already several species of wallabies, rat kangaroos, bandicoots and the marsupial wolf either are, or are on the verge of becoming, extinct. This is particularly so in the open districts of the southern half of the continent, and the Commonwealth Government is now considering the establishment of a fauna park in the vicinity of Canberra. The unique lyre-bird is reported to be holding its own against the fox and the cat ; but the striped marsupial wolf may already be extinct. The article also contains an account of the effect of disturbances of the native fauna on general biological relationships.