These abstract characterizations, however, can convey little meaning without the evidence on which they rest. What does "constitutionally disruptive" imply, and what "constitutionally synthetic"? It is a far cry from humanity to the cochineal insect, yet this may serve as our point of departure. The well-known dye derived from this species is elaborated entirely by the females, who store it in huge quantities and as a result are condemned to a life of quietude on the sustaining cactus. The males, on the other hand, are small in size, quick in movement and short-lived.
This division of labor, though somewhat pronounced, is not a biological freak; it can be matched, more or less closely, many times, not only among insects, but among other animals, both lower and higher in the scale of being. Sexual differentiation among birds and mammals, however, manifests itself not by some one glaring difference of habit, but usually in smaller ways; in ourselves, in the sudden and strenuous outbursts of activity, characteristic of men, especially of young men, boys and barbarians, and in the patient, long-continued, and less violent expenditure of energy ordinarily seen in women.
Of course these distinctions are broad and have no bearing on individual cases. They serve rather as convenient, though well-founded rubrics under which to array the leading characteristics of the two temperaments whose existence affects our daily conduct in a hundred ways. Nor is this dealing with averages, whose constituent items merge unrecognizably in the multitude, disadvantageous, for in matters that seem to involve a whole kind, evidence from this or that individual affects the general result no more than my tall friend makes the average height of men other than it is.
While the males and females of fishes, reptiles and amphibians, follow the rule of the cochineal insect, exactly the reverse is true of birds and mammals, for among these the males are practically always the larger. In reality, however, maleness and femaleness are fundamentally unaltered throughout the living world, and the apparently contradictory evidence from the higher forms of life is traceable to their peculiar habits of reproduction.
Most important of all in this connection is brooding, for it throws light, from two angles at least, on the physical superiority of the male sex. Maternity, whether in birds or mammals, demands tremendous sacrifices—in fact is the very thing responsible for their higher development. Moreover, these sacrifices are not laid down in one lump sum, but bit by bit, and it may take years before all the premiums needed to insure a new life completely have been paid up.
Greater, albeit subtler, effects than come from these drains, are traceable to the inevitable stagnation of females incapacitated by incubation or pregnancy, for the quietude necessitated by these states is