Must not the logical consequence of such positive language be, that man forms a zoological family comprising several genera and many species, precisely similar to the family of anthropoid apes? But no; Agassiz devotes a new paragraph to declaring that this opinion, which he has expressed so clearly, agrees entirely with the theory of unity, and in no way brings human fraternity into question. In one of his first memoirs upon questions of this nature, he declared that _man is an exceptional being_, and we shall see how far he pushes this unavoidable consequence of his theories. In a letter addressed to the same authors, and printed in the _Indigenous Races of the Earth_, Agassiz returns to the same subject. He here insists upon considerations which, in his first work, he had merely alluded to, and which we are truly astonished to receive from his pen. In order to show that the same local causes have acted upon man and animals, he draws attention to the resemblance of colour, which, according to him, exists between the complexion of the Malay and the colour of the hair of the Orang; from the same point of view he compares the Negrittoes and Telingas with the gibbons. If it were possible to consider seriously this comparison between the skin of a human group, and the colour of the hair of an animal, we should have no lack of arguments to bring against the author. I shall only remind my readers that black gibbons are found in Sumatra, which is one of those islands where men are considered by Agassiz to resemble the orang in colour. Carried away by the heat of controversy with those naturalists who admit the unity of the geographical origin of man, Agassiz goes much further than this. He considers the various languages as being of primitive origin as well as all other characters. Men, he asserts, were created by nations, each of which appeared upon the globe with its own language. He draws a comparison between these languages and the voices of animals; he laughs at philologists for their belief in the discovery of any connection between one language and another. In his opinion, there is just as much relation between one human language and another, as between the growling of different species of bears, the mewing of the cats of the two continents, the quacking of ducks, or the song of thrushes, who all pour forth their gay and harmonious notes, each in its dialect, which is neither inherited nor derived from another.