Préparationof manuscripts: Manuscripts should be written in English. They should be typewritten originals with a wide margin and ample spaces between the Unes. One extra copy will facilitate the editor's task. Papers should be provided with an abstract not exceeding 200 words, a list of contents, a list of captions of figures and a list of références. Footnotes should be given in the text between Unes and not in the list of références. Références should be numbered in the text between square brackets. Figures should be originals, drawn in India ink and with sufficiently large lettering to remain legible after réduction by the printer. Subscriplions: PHYSICS REPORTS is published as a review section of PHYSICS LETTERS. Each volume of PHYSICS REPORTS contains approximately 400 pp. PHYSICS REPORTS can be subscribed to separately. The price per volume amounts to Dfl. 272.00postage included. Single copies of issues will be made available at a price which will dépend on the size of the issue concerned.