usually go hopelessly to pieces in the next generation. The longer a useful type has been maintained the more stable it is. (3) That artificial conditions tend to produce variation is obvious in every civilisation. The more intense is the artificiality of life, the greater are the extremes of ability and incompetence, of riches and poverty, accompanying it. It is often a problem to kind hearts that there should be such misery and degradation side by side with the ease and welfare of civilisation. The answer is that it is inevitable, because the very same artificiality which gives scope to the capable to rise, equally gives scope for the incapable to fall. Every chance, every opening, every benefit attainable by exertion, is a means of advance to him who uses it; but it is accompanied by equal chances of failure, equal openings to loss, equal injuries resulting from sloth, which are the equally sure means of degradation for those who have not the wit or energy to avoid them. The "submerged tenth" is the inevitable complement of the leading tenth. (4) Greater variability of mind accompanies unusual development; this is seen in the great outbursts of mental activity which have occurred along with external expansion in the times of Elizabeth and of Victoria. Or in earlier times the growth of Greek literature following the Periclean expansion, or of Roman literature with the Augustan settlement of the world. (5) Mental growth is directed and encouraged by use. This fact is so obvious that it is proverbial, as in the saying, "The mind grows by what it feeds upon." All mental training and teaching recognise this, but it is true in later life as well as in youth. It is well known how in the least civilised races small children are as advanced—or more so—than in higher races. The Australian is said to come to a standstill at ten or twelve years old. The Egyptian seldom advances mentally after sixteen. A low-class Englishman does not improve after twenty or so. A capable man will continue to expand till thirty or forty. And the man of the greatest capacity will continue to grow mentally, and assimilate new lines of thought, until seventy or eighty. Thus the greater the power of use and the activity of the mind, the longer will it continue to grow. This may well be regarded as one of the main tests of a great mind; and it is strictly in accord with the system of the well-known embryonic changes passing from lower to higher stages, and continuing to grow in development into higher and higher types. The savage ceased to grow mentally even while in childhood; the sage continues the expansion of mind to extreme old age.