A Textbook of Mental Deficiency (Amentia)

to treat of the inheritance and transmission of mental deficiency with any degree of precision. Dr. Tredgold inveighs against the all-too-common belief that genius is so intimately connected with insanity that we must cheerfully put up with the latter for the sake of the former. He maintains that the great majority of men and women of outstanding ability have been particularly sane and have come of sane and healthy stocks. This view does not altogether coincide with that of Havelock Ellis who, in his compendious Study of British Genius, states that, men of high intellectual ability generally display a lack of muscular co-ordination and usually suffer from extreme shyness, bashfulpess or timidity. The whole question is made no easier to understand when we study the chapter devoted to ' Idiots Savants Dr. Tredgold cites a case, reported by Dr. L. Lotte of Armentieres, of a young man who had developed an extraordinary* faculty of calculating. When he was asked how many grains of corn there would be in anv one of 64 boxes, with 1 in the first, 2 in the second. 4 in the third, 8 in the fourth, and so on, he gave the