Like other religions, those of the Celtic lands of Europe supplemented the earlier animism by a belief in spirits, who belonged to trees, animals, rocks, mountains, springs, rivers, and other natural phenomena, and in folk-lore there still survives abundant evidence that the Celt regarded spirits as taking upon themselves a variety of forms, animal and human.  It was this idea of spirits in animal form that helped to preserve the memory of the older totemism into historic times.  It is thus that we have names of the type of Brannogenos (son of the raven), Artogenos (son of the bear), and the like, not to speak of simpler names like Bran (raven), March (horse), surviving into historic times.  Bronze images, too, have been found at Neuvy-en-Sullias, of a horse and a stag (now in the Orleans museum), provided with rings, which were, as M. Salomon Reinach suggests, probably used for the purpose of carrying these images in procession.  The wild boar, too, was a favourite emblem of Gaul, and there is extant a bronze figure of a Celtic Diana riding on a boar’s back.  At Bolar, near Nuits, there was discovered a bronze mule.  In the museum at Mayence is a bas-relief of the goddess of horses, Epona (from the Gaulish Epos=Lat. equus, horse), riding on horseback.  One of the most important monuments of this kind is a figure of Artio, the bear-goddess (from Celtic Artos, a bear), found at Muri near Berne.  In front of her stood a figure of a bear, which was also found with her.  The bull of the Tarvos Trigaranos bas-relief of Notre Dame was also in all likelihood originally a totem, and similarly the horned serpents of other bas-reliefs, as well as the boar found on Gaulish ensigns and coins, especially in Belgic territory.  There is a representation, too, of a raven on a bas-relief at Compiegne.  The name ‘Moccus,’ which is identified with Mercury, on inscriptions, and which is found inscribed at Langres, Trobaso, the valley of the Ossola and the Borgo san Dalmazzo, is undoubtedly the philological equivalent of the Welsh moch (swine).  In Britain, too, the boar is frequently found on the coins of the Iceni and other tribes.  In Italy, according to Mr. Warde Fowler, the pig was an appropriate offering to deities of the earth, so that in the widespread use of the pig as a symbol in the Celtic world, there may be some ancient echo of a connection between it and the earth-spirit.  Its diet of acorns, too, may have marked it out, in the early days of life in forest-clearings, as the animal embodiment of the oak-spirit.  In the legends of the Celtic races, even in historic times, the pig, and especially the boar, finds an honoured place.  In addition to the animals aforementioned, the ass, too, was probably at one time venerated in one of the districts of Gaul, and it is not improbable that Mullo, the name of a god identified with Mars and regarded as the patron of muleteers, mentioned on inscriptions (at Nantes, Craon, and Les Provencheres near Craon), meant originally