Could we remove their prison clothing, dress them as ordinary citizens dress, and mingle them with a mass of ordinary citizens, I venture to say that no scientist would be able to detect the criminals by the formation of their heads or the size of their ears. I do not maintain that men who possess queer-shaped heads do not commit crime. This is far from being the case. Unfortunately they do, and very serious crime too; but I do maintain that the perpetration of crime was caused not by the shape of their heads, but by causes that exist independently of it. We have, of course, a very large number of degenerates, but every degenerate does not possess an ill-formed head. Neither is every degenerate a criminal. Many of them are happy enough, and innocent enough when they can get enough to eat and places wherein to sleep. But when deprived of these things they may steal, beg, sleep out, or commit some other offence that brings them within the meshes of the law, and become criminals. They become criminals not because they possess criminal minds, but because there is no place for them in our social and industrial life; because their necessities cannot be supplied in any other way. To classify such people as criminals is about as wise and just as classifying babes as criminals! Though they form a considerable proportion of our prison population, they are not to be detected by their ill-shaped heads, for some that are declared to be feeble-minded are quite up to the ordinary standard of beauty. But there is another kind of degeneracy that cannot be mistaken, because it can be easily ascertained and established. I now refer to the physical measurements of prisoners. For many years it has been noted both in Europe and America that juvenile prisoners are much inferior in height, weight, muscular strength and capacity to the average height, weight and strength of the industrial population of similar age. Our own Prison Commissioners have for ten years conducted an examination in Pentonville prison of all prisoners between the ages of 16 years and 21 years. They have given us the results in words and figures that compel thought. Once more I give their words: “They are as a class two inches shorter and fourteen pounds lighter than the average industrial population of similar ages, and 28 per cent. of them suffer from some disease, affliction, or deprivation,” and the Commissioners add that the highest proportion of reconvictions comes from among them, being no less than 40 per cent. As nearly 1400 of such prisoners pass through Pentonville every year, and as, moreover, the examination extended over a series of years, it will be admitted that the results may be taken as not only correct with regard to Pentonville, but taken also as an accurate description of our youthful prisoners generally, so far as large towns are concerned.