Man himself has done much toward arousing and cultivating the imitative faculty in the dog (which, in the beginning, impelled this highly developed animal to _answer_ his master, thus originating the first vocables--barking--in the canine language), by conversing with him. In all probability, it is only an "anatomical barrier and a psychical accident" at best, which prevent the dog from addressing his master through the agency of speech itself!
The dog's voice is exceedingly pleasing to himself, and, most frequently, when "baying the moon," he is listening to his own singing, _not_ (as is generally supposed) as it pours forth from his throat, but in a more pleasing manner, as it is breathed back to his listening ears from the airy lips of Echo!
That dogs have discovered that pleasing phenomenon, the echo, I do not question for a single instant. If a dog which is in the habit of "baying the moon" be watched, it will be observed that he invariably selects the same spot or spots for his nocturnal concerts. If you happen to be standing in the neighborhood, you will also notice that there is always an echo, more or less distinct, of his barking; and, if you will observe closely, you will see that the dog listens for this echo, and that he will not resume his song until it (the echo) has entirely ceased. That this is the true explanation of "baying the moon" (where there is not another dog in the distance whose clamorous barkings have aroused a like performance on the part of the animal under observation), the following instance, coming under my own observation, would seem to indicate.
I had frequently noticed that a spaniel crept under a honeysuckle bush in my front yard whenever he gave one of his serenades. Time and again I tried to hear the echo, but in vain, and an almost verified fact seemed in danger of total annihilation. Finally, it occurred to me to dispossess the dog and take his place beneath the bush. I called him out and succeeded with much difficulty in getting beneath the bush, from whence I, imitating his voice, sent several howling barks. My theory was no longer merely theory, but was, instead, a verified fact, for, sharp, clear, and distinct, the echoes of my voice came back from some buildings an eighth of a mile away! Some peculiar acoustic environment made it impossible to get the echo at any place, as far as I could discover, other than beneath the bush.[62]