3 oo THE POPULAR SCIENCE MONTHLY 



These abstract characterizations, however, can convey little meaning 

 without the evidence on which they rest. What does " constitutionally 

 disruptive" impty, 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 bio- 

 logical 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 indi- 

 vidual cases. They serve rather as convenient, though well-founded 

 rubrics under which to array the leading characteristics of the two tem- 

 peraments whose existence affects our daily conduct in a hundred ways. 

 Nor is this dealing with averages, whose constituent items merge un- 

 recognizably 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, fol- 

 low 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 develop- 

 ment. 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 incu- 

 bation or pregnancy, for the quietude necessitated by these states is 



