of the women in receptivity and memory, and a slight superiority of the men in control of movement and in thought about concrete mechanical situations. In interests which cannot be so definitely measured, women seem to be more interested in people and men in things. In instinctive equipment women excel in the nursing impulse and men in the fighting impulse. In physical equipment men are stronger and bigger than women. They excel in muscular tests in ability to "spurt," whereas women do better in endurance tests. The male sex seems on the whole to be slightly more variable than the female, i.e., its curve of distribution is somewhat flatter and extends both lower and higher than does that of the female; or, stated another way, men furnish more than their proportion of idiots and of geniuses. Slight though these differences are, they are not to be disregarded, for sometimes the resulting habits are important. For instance, girls should be better spellers than boys. Boys should excel in physics and chemistry. Women should have more tact than men, whereas men should be more impartial in their judgments. With the same intellectual equipment as women, men should be found more often in positions of prominence because of the strength of the fighting instinct. The geniuses of the world, the leaders in any field, as well as the idiots, should more often be men than women. That these differences do exist, observation as well as experiment prove, but that they are entirely due to essential innate differences in sex is still open to question. Differences in treatment of the sexes in ideals and in training for generation after generation _may_ account for some of the differences noted. What these differences mean from the standpoint of practice is still another question. Difference in equipment need not mean difference in treatment, nor need identity of equipment necessarily mean identity of training. The kind of education given will have to be determined not only by the nature of the individual, but also by the ideals held for and the efficiency demanded from each sex.