PROF. MAJOR GREENWOOD delivered the second of his Heath Clark Lectures, under the auspices of the National Institute of Industrial Psychology, on May 20, on “Temperaments, Physical and Psychological, in Modern Science”. He pointed out that the ancient physicians were deeply conscious that differences of temperament entailed psychological consequences which expressed themselves in bodily as well as mental reactions, and that it was the duty of the physician to diagnose and treat these conditions. In Great Britain the work of Kretschmer has received considerable attention, but the infinitely clearer and scientifically more rigorous work of Boldrino and the Italian School has been unduly neglected. Boldrino has shown that it is probable that certain morphological types, roughly corresponding to the old 'sanguine’ and ‘melancholies', do differ in resistance to such diseases as tuberculosis, in distribution through the social classes, and even in fertility, but in respect of psychological characters there is much less evidence of any such relation. Prof. Greenwood considered the claims of some modern work on temperament that had relied on statistical correlations: he emphasised that statistical description is fundamentally group-description only, and has little diagnostic value in individual cases. He illustrated this by data on accidents, and showed that, while the application of tests would undoubtedly eliminate many likely to be accident prone, yet they would also eliminate some who are not, and so do an injustice to individuals. Although Prof. Greenwood feels that, with respect to a finer gradation of temperamental qualities, we are indefinitely far from any fool-proof system of routine testing, yet we may be near to the time when an elimination of extreme variants on a basis of temperamental tests will be practicable.