quires or expends on his own account and for the exercise of his own personal functions he can not transmit again by generation to other individuals.
It is certainly not proper to push the preceding biological inductions, the truth of which is only general, to extremes. Mr. Spencer himself has not always kept the measure or avoided inexact intepretations of the laws in question. Practically, and in the actual condition of affairs, the superior races and the individuals belonging to those races, do not lose their generative power except when they give themselves up to what we might call intellectual debauchery. But sterility rarely comes from this cause. Man can nearly always, even when he abandons himself to mental labors, maintain a procreative power fully equivalent to that of the woman with whom he is mated, and it is unreasonable to demand more of him. It is, then, the woman that must be considered, looking at the question from this point. Mr. Spencer remarks, in support of his thesis, that the women among the higher classes, in whom mental labor is carried to excess, are relatively infertile; but there are also several elements to be distinguished here. The women of Paris have, for instance, a weight of brain which, according to the anthropologists, raises them but little above negresses: they should, then, by the theory we are considering, be very fertile, like the negresses; but the contrary is the case. The real reason of this is, that while the brain of a Parisian woman is definitively but little overstocked with ideas, her whole body is still less developed than her brain; but it is not so with the strong-limbed negresses. Why has the body of the Parisian woman been arrested in its development? Do not lay it to her intelligence, but to her want of intelligence, to costumes and fashion, to bad hygienic conditions, to parties, vigils, balls, and theatres; to the activity, at the same time feverish and frivolous, of a wholly worldly life in an air more or less vitiated. In the same way, if the daughters of aristocratic families are relatively infertile, there is nothing to prove that their infertility arises from mental labor. In short, whenever mental labor is really a cause of diminished fertility, it is so by being excessive, and not by its Well-regulated exercise. The same is the case with every excess of labor, even physical; the common workman or laborer may exhaust himself as much as the thinker. Mr. Spencer has not sufficiently distinguished here between the normal and the exaggerated exercise of the brain. A normal exercise, in which the functional expenditure is not above the nutrition of the organs, but below it, does not appear to us to diminish fecundity, or, at least, does not diminish it enough to trammel the development of the species. In the normal individual, intellectual productivity and sexual productivity march in line; they are, as it were, the two poles at which the excess of nutrition is expended after a right fashion; but, in case one of the poles draws all to itself, it is evident that the other pole will lose correspondingly. The almost exclusive
