IN a short article in Scientia (Aug. 1932, p. 84) Dr. J. Needham discusses the problem of organisation and its place in the biological thought of the present day. Organisation is a property of all matter, and the organisation of living things is at one with material organisation, even if on a grade of its own. It is not something which controls or directs the material system, but is bound up with, and inseparable from, the organised matter itself. From this point of view organisation in the biological sense is something integral with the rest of scientific data, which science can take into account; and it will probably make necessary a widening and stretching of the classical concepts of physics and chemistry rather than an abandonment of them, so that a new mechanism will be evolved to include the modes of action and the organising relations found in living systems. Herein lies the central problem of biology, and biology will make progress only when, as has happened in physics and chemistry, attention is given to the theoretical principles which underlie and would co-ordinate the multifarious studies and researches of the field and the laboratory.