The human species

by A. de Quatrefages

I subjoin some of these relations taken from a table of Duvernoy, and in which the weight of the brain is taken as unity.

Man	{ Infant	1 : 22	Rodents	{ Field Mouse	1 : 31
	{ Youth	1 : 25		{ Mouse	1 : 43
	{ Adult	1 : 30
	{ Old	1 : 35	Carnivora	{ Mole	1 : 36
				{ Dogs 1 : 47	1 : 305
Apes	{ Saimiri	1 : 22	Birds	{ Blue Tit	1 : 12
	{ Saï	1 : 25		{ Canary	1 : 14
	{ Ouisititi	1 : 28		{ Cole Tit	1 : 18
	{ Gibbon	1 : 48		{ Sparrow	1 : 25
				{ Chaffinch	1 : 27

The man in question is the European White. Now from this table we see that from infancy to old age the relation of the brain to the rest of the body keeps diminishing. Are we to conclude then from this that the youth is degraded relatively to the infant, and that the adult or the old man has assumed a simian character?

We see, moreover, that there ought to be some understanding as to the word simian itself. If the gibbon, which belongs to the type of our supposed ancestors, has a brain relatively smaller than ours, it is otherwise with the three members of the genus cebus given in the table. The latter are superior to the anthropoid; the two first show exactly the same relation as the infant and youth; the third surpasses the adult man. But all three are surpassed by the two tits and the canary.

Consequently, if we are right in regarding the human race, or the human individual whose brain is below the mean by several grammes, as tending towards the anthropoid ape, we ought to consider the race, or the individual whose brain is above the mean as approximating to the cebus, or even the passerines or conirostres. If the first comparison is admissible, the second is equally so.

We can then say with the learned anatomist whose authority I have so often appealed to: “The microcephali, however reduced their brain may be, are not brutes; they are merely undeveloped men.” Or again, we may say with M. Best, whose testimony cannot be suspected in such a matter, that in their development apes do not resemble man, and, conversely, that the human type when degraded does not resemble the ape.

IX. From the pithecoid man of Darwin and Haeckel, from the speechless man who used his teeth as weapons, to the man of our age, the distance is still very great. How has it been filled up? How has this intelligence been developed which is able in many cases to hold nature herself in subjection? It is Wallace who has especially answered this question in the name of the theory of which he is one of the founders. We shall see at the same time that he admits the imperfection of this theory, when he discusses the peculiar attributes of the human species.

It is well known that this naturalist shares with Darwin and M. Naudin, the honour of having sought in natural selection for an explanation of organic origins. But our fellow countryman has confined himself to a sketch the fundamental character of which he has recently entirely modified. Darwin has embraced the problem as a whole and in its details; he has added to his first work several publications upon subjects very different in appearance, but all of which tend to the same end. He may with justice be considered as the chief of the school.

Wallace, who almost anticipated Darwin in the publication of ideas which are common to both, recognises him as his master on all occasions. He has discussed a small number of points in special memoirs which never cover much ground. From not attempting the solution of all the questions suggested by the theory, he has neither met with so many or such serious difficulties as his eminent rival. This, perhaps, explains the fact that he generally shows himself more precise and logical. He therefore, always possessed considerable authority among the partisans of Darwinism, until he published his special views on man.

According to Wallace, immediate and personal utility is the only cause which sets selection in action. This is fundamentally the theory of Darwin; but the latter has allowed himself to be influenced by comparisons or metaphors, which have raised sharp criticisms, which have perhaps deceived him, and which he employs more or less to evade his difficulties. We never meet with the same in Wallace, who accepts all the consequences to which his absolute principle leads him.