Darwin has mentioned the frequent action of the 'snarling muscle,' by which, in sneering, our upper canine teeth are exposed, like those of a dog prepared to fight.
Monkeys and apes possess vocal sacs, especially large in the orang-utan; survivals of them, although no longer used, persist in man in the shape of a pair of small diverticula, the pouches of Morgagni, between the true and the false vocal cords.
'In the native Australians, the dental formula appears least removed from the hypothetical original type, for in it are still found complete rows of splendid teeth, with powerfully-developed canines and molars, the latter being either uniform, or even increasing in size, as we proceed backwards, in such a way that the wisdom tooth is the largest of the series. This is decidedly a pithecoid characteristic which is always found in apes. The upper incisors of the Malay, apart from their prognathous disposition, have occasionally a distinctly pithecoid form, their anterior
