120 SPECIAL EXPRESSIONS: CHAP. V. Sir W. Scott's famous Scotch greyhound, Maida, had this habit, and it is common with terriers. I have also seen it in a Spitz and in a sheep-dog. Mr. Riviere, who has particularly attended to this expression, informs me that it is rarely displayed in a perfect manner, but is quite common in a lesser degree. The upper lip during the act of grinning is retracted, as in snarling, so that the canines are exposed, and the ears are drawn backwards; but the general appearance of the animal clearly shows that anger is not felt. Sir C. Bell3 remarks " Dogs, in their expression of fondness, have a slight eversion of the lips, and grin and sniff amidst their gambols, in a way that resembles laughter." Some persons speak of the grin as a smile, but if it had been really a smile, we should see a similar, though more pronounced, move- ment of the lips and ears, when dogs utter their hark of joy; but this is not the case, although a bark of joy often follows a grin. On the other hand, clogs, when playing with their comrades or masters, almost always pretend to bite each other; and they then retract, though not encrgeticalty, their lips and ears. Hence I suspect that there is a tendency in some dogs, whenever they feel live- ly pleasure combined with affection, to act through habit and association on the same muscles, as in playfully bit- ing each other, or their masters' hands. I have described, in the second chapter, the gait and appearance of a dog when cheerful, and the marked antithesis presented by the same animal when dejected and disappointed, with his head, ears, body, tail, and chops drooping, and eyes dull. Under the expectation of any great pleasure, dogs bound and jump about in an extravagant manner, and bark for joy. The tendency to bark under this state of mind is inherited, or runs in * ' The Anatomy of Expression,' 1844, p. 140.