This chapter examines the successful occupation of a part of England by Hungarian frogs. Until recently, the animals of England included two species of frog, and two of toad. The common frog, Rana temporaria, is found all over the country. The edible frog, Rana esculenta, is not so common, and has very likely been introduced, either by monks, epicures or amateur naturalists. Professor A. V. Hill, the physiologist, who was a Conservative M. P. in the last Parliament, used to import frogs of the species Rana ridibunda from Hungary. The Brekekekex sound, which they make during the day-time, has been compared with that of a machine gun, the Koax with the noise made by a cat when you tread on its tail. In captivity they will mate with the edible frogs and produce tadpoles, but no one knows whether or not the hybrids are fertile.