For numerous and interesting details on the resemblance of dogs and jackals see Isid. Geoffroy St.-Hilaire 'Hist. Nat. Gen.' 1860 tome 3 page 101. See also 'Hist. Nat. des Mammiferes' par Prof. Gervais, 1855 tome 2 page 60.) says that not one constant difference can be pointed out between their structure and that of the smaller races of dogs. They agree closely in habits: jackals, when tamed and called by their master, wag their tails, lick his hands, crouch, and throw themselves on their backs; they smell at the tails of other dogs, and void their urine sideways; they roll on carrion or on animals which they have killed; and, lastly, when in high spirits, they run round in circles or in a figure of eight, with their tails between their legs. (1/22. Also Guldenstadt 'Nov. Comment. Acad. Petrop.' tome 20 pro anno 1775 page 449. Also Salvin in 'Land and Water' October 1869.) A number of excellent naturalists, from the time of Guldenstadt to that of Ehrenberg, Hemprich, and Cretzschmar, have expressed themselves in the strongest terms with respect to the resemblance of the half-domestic dogs of Asia and Egypt to jackals. M. Nordmann, for instance, says, "Les chiens d'Awhasie ressemblent etonnamment a des chacals." Ehrenberg (1/23. Quoted by De Blainville in his 'Osteographie, Canidae' pages 79, 98.) asserts that the domestic dogs of Lower Egypt, and certain mummied dogs, have for their wild type a species of wolf (C. lupaster) of the country; whereas the domestic dogs of Nubia and certain other mummied dogs have the closest relation to a wild species of the same country, viz. C. sabbar, which is only a form of the common jackal. Pallas asserts that jackals and dogs sometimes naturally cross in the East; and a case is on record in Algeria. (1/24. See Pallas in 'Act. Acad. St. Petersburgh' 1780 part 2 page 91. For Algeria, see Isid. Geoffroy St.-Hilaire 'Hist. Nat. Gen.' tome 3 page 177. In both countries it is the male jackal which pairs with female domestic dogs.) The greater number of naturalists divide the jackals of Asia and Africa into several species, but some few rank them all as one.
I may add that the domestic dogs on the coast of Guinea are fox-like animals, and are dumb. (1/25. John Barbut 'Description of the Coast of Guinea in 1746.') On the east coast of Africa, between latitude 4 deg and 6 deg 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 (1/26. 'Travels in South Africa' volume 2 page 272.) 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 extinct mammals, so that its introduction must have been ancient. (1/27. Selwyn, Geology of Victoria; 'Journal of Geolog. Soc.' volume 14 1858 page 536 and volume 16 1860 page 148; and Prof. M'Coy in 'Annals and Mag. of Nat. Hist.' (3rd series) volume 9 1862 page 147. The Dingo differs from the dogs of the central Polynesian islands. Dieffenbach remarks ('Travels' volume 2 page 45) that the native New Zealand dog also differs from the Dingo.)
From this resemblance of the half-domesticated dogs in several countries 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 are descended from two well-defined species of wolf (viz. C. lupus and C. latrans), and from two or three other doubtful species (namely, the European, Indian, and North African wolves); from at least one or two South American canine species; from several races or species of jackal; and perhaps from one or more extinct species.