I may add that the domestic dogs on the coast of Guinea are fox-like animals, and are dumb.[29] On the east coast of Africa, between lat. 4° and 6° south, and about ten days' journey in the interior, a semi-domestic dog, as the Rev. S. Erhardt informs me, is kept, which the natives assert is derived from a similar wild animal. Lichtenstein[30] says that the dogs of the Bosjemans present a striking resemblance even in colour (excepting the black stripe down the back) with the _C. mesomelas_ of South Africa. Mr. E. Layard informs me that he has seen a Caffre dog which closely resembled an Esquimaux dog. In Australia the Dingo is both domesticated and wild; though this animal may have been introduced aboriginally by man, yet it must be considered as almost an endemic form, for its remains have been found in a similar state of preservation and associated with {26} extinct mammals, so that its introduction must have been ancient.[31] From this resemblance in several countries of the half-domesticated dogs to the wild species still living there,--from the facility with which they can often be crossed together,--from even half-tamed animals being so much valued by savages,--and from the other circumstances previously remarked on which favour their domestication, it is highly probable that the domestic dogs of the world have descended from two good species of wolf (viz. _C. lupus_ and _C. latrans_), and from two or three other doubtful species of wolves (namely, the European, Indian, and North African forms); from at least one or two South American canine species; from several races or species of the jackal; and perhaps from one or more extinct species. Those authors who attribute great influence to the action of climate by itself may thus account for the resemblance of the domesticated dogs and native animals in the same countries; but I know of no facts supporting the belief in so powerful an action of climate.