The lung capacity of women is less, and they consume less oxygen and produce less carbonic acid than men of equal weight, although the number of respirations is slightly higher than in man. On this account women suffer deprivation of air more easily than men. They are not so easily suffocated, and are reported to endure charcoal fumes better, and live in high altitudes where men cannot endure the deprivation of oxygen.[68] The number of deaths from chloroform is reckoned as from two to four times as great in males as in females, and this although chloroform is used in childbirth. Children also bear chloroform well.[69] Women, like children, require more sleep normally than men, but "Macfarlane states that they can better bear the loss of sleep, and most physicians will agree with him.... One of the greatest difficulties we have to contend with in nervous men is sleeplessness, a result, no doubt, of excessive katabolism."[70] Loss of sleep is a strain which, like gestation, women are able to meet because of their anabolic surplus. The fact that women undertake changes more reluctantly than men, but adjust themselves to changed fortunes more readily, is due to the same metabolic difference. Man has, in short, become somatically a more specialized animal than woman, and feels more keenly any disturbance of normal conditions, while he has not the same physiological surplus as woman with which to meet the disturbance. Lower forms of life have the remarkable quality of restoring a lost organ, and of living as separate individuals if divided. This power gradually diminishes as we ascend the scale of life, and is lost by the higher forms. It is a remarkable fact, however, that the lower human races, the lower classes of society, women and children, show something of the same quality in their superior tolerance of surgical disease. The indifference of savage races to wounds and loss of blood has everywhere been remarked by ethnologists. Dr. Bartels has formulated the law of resistance to surgical and traumatic treatment in the following sentence: "The higher the race, the less the tolerance, and the lower the culture-condition in a given race, the greater the tolerance."[71] The greater disvulnerability of women is generally recognized by surgeons. The following figures from Lawrie, Malgaigne, and Fenwick are representative:[72] LAWRIE (GLASGOW)