Cynoidea

Section of fi ipede Carnivora, characterized by their digitigrade progre ion, non-retractile claws, five-toed forefeet and four-toed hindfeet, smooth tongue, and large tympanic bulle. There are four præmolars, in front of two upper and three lower molars. All form one family, Canidæ, including the genus Vulpes (Foxes), with vertical slit-like pupil, and Canes (Dogs), with round pupils. The domestic dog has probably come from several wild species, the larger from the Wolf, the smaller varieties from Jackal-like forms. Some of the domestic breeds date back to prehistoric times. The Dingo of Australia is perhaps the only true wild dog known. Other forms are probably reversions from domestic importations, as in New Zealand. The eye is rounder in the dog, more oblique in the wolf. The ears are erect in the former, and drooping in the latter. The wolf hangs his tail, and howls instead of barking. Dogs readily become feral and lose their distinctive color marks and their habit of barking. The period of gestation, 60 to 67 days, is the same for dog and wolf; they readily interbreed, producing fertile offspring.