It is of interest to note, in passing from this question, that inherent facts of the human constitution would interdict us if we thought it a fit ideal to breed for stature or bulk. Giants are essentially morbid--not favourable but unfavourable variations. They are very frequently childless and almost constantly slow-witted. Their condition is really a mild form of a well-marked and highly characteristic disease known as acromegaly, and distinguished by great enlargement of the face and extremities. The malady depends upon peculiarities in the glandular activities of the body: _and the state of these which makes for great stature and bulk makes against intelligence_. It is suggested, then, that any considerable increase of human bulk and stature could only be obtained at the cost of intelligence. It would be very dear at the price. When we come to the subject of selection for parenthood in man through the preferences exhibited by individuals for members of the opposite sex, we shall see that what Darwin called “sexual selection” is certainly a reality in the case of man, whether or not it be so in the case of the lower animals. We shall see that this most potent factor in human evolution acts even now very favourably, and is capable of having its value enormously enhanced. In the selection of husbands, nervous or psychical factors are notably of high survival-value in civilised communities. In the selection of wives the survival-value of the physical is still very high: but it may be hoped and believed that the present tendency is to attach relatively less importance to them and more to the psychical elements of the chosen. This tendency must be furthered to the utmost point beyond which the physical requisites for motherhood would suffer weakening--but no further. =How are we to estimate civic worth?=--We have already observed that it is incorrect to use the word “fit” as if it were synonymous with “worthy.” If we insist on using this term, which means only “adapted to conditions,” we must define those conditions. We must say that we desire to further the production of those who are fit for citizenship, and to disfavour the production of those who are unfit for citizenship. We shall thereby dispose at least of those vexatious objectors who tell us that many eminent criminals are individually superior to many eminent judges. The statement is doubtless untrue, but if it were true it would still be irrelevant. A criminal may be individually a remarkable personality, but in so far as he is a criminal he is unfit for citizenship. It is far better to use consistently Mr. Galton's phrase, “civic worth,” or, for short, “worth.” We may here note Mr. Galton's most recent remarks on what he means by worth:--