Upon this simple principle (or rather precedent) the sociological doctor drives gaily ahead. When a crapulous tyranny crushes men down into the dirt, so that their very hair is dirty, the scientific course is clear. It would be long and laborious to cut off the heads of the tyrants; it is easier to cut off the hair of the slaves. In the same way, if it should ever happen that poor children, screaming with toothache, disturbed any schoolmaster or artistic gentleman, it would be easy to pull out all the teeth of the poor; if their nails were disgustingly dirty, their nails could be plucked out; if their noses were indecently blown, their noses could be cut off. The appearance of our humbler fellow-citizen could be quite strikingly simplified before we had done with him. But all this is not a bit wilder than the brute fact that a doctor can walk into the house of a free man, whose daughter’s hair may be as clean as spring flowers, and order him to cut it off. It never seems to strike these people that the lesson of lice in the slums is the wrongness of slums, not the wrongness of hair. Hair is, to say the least of it, a rooted thing. Its enemy (like the other insects and Oriental armies of whom we have spoken) sweep upon us but seldom.