The myth of the dog is one of those of which the interpretation is more delicate. As the common dog stays upon the doorstep of the house, so is the mythical dog generally found at the gate of the sky, morning and evening, in connection with the two Açvinâu. It was a fugitive phenomenon of but an instant's duration which determined the formation of the principal myth of the dog. When this moment is past, the myth changes its nature. I have already referred to the French expression, "entre chien et loup," as used to denote the twilight;[29] the dog precedes by one instant the evening twilight, and follows by one instant that of morning: it is, in a word, the twilight at its most luminous moment. Inasmuch as it watches at the gates of night, it is usually a funereal, infernal, and formidable animal; inasmuch as it guards the gates of day, it is generally represented as a propitious one; and as we have seen that, of the two Açvinâu, one is in especial relation with the moon, and the other with the sun, so, of the two dogs of mythology, one is especially lunar, and the other especially solar. Between these two dogs we find the bitch their mother, who, if I am not mistaken, represents now the wandering moon of heaven, the guiding moon that illumines the path of the hero and heroine, now the thunderbolt that tears the cloud, and opens up the hiding-place of the cows or waters. We have, therefore, thus far three mythical dogs. One; menacing, is found by the solar hero in the evening at the western gates of heaven; the second, the more active, helps him in the forest of night, where he is hunting, guides him in danger, and shows him the lurking-places of his enemies whilst he is in the cloud or darkness; the third, in the morning, is quiet, and found by the hero when he comes out of the gloomy region, towards the eastern sky.