29 JULY 1960, Page 24

False Scent. By Ngaio Marsh. (Collins, 12s. 6d.) The kind

of detective novel that flour- ished thirty years ago, when all the world was young, and English detectives were well-bred into the bargain, and when famous, fading and pas- sionately selfish actresses were always getting murdered under the same roof where all their rivals, enemies, lovers, husbands, put-upon ser- vants, exploiters and exploitees were gathered together, so as to provide enough red herrings, false clues and surprise denouements to fill 256 pages. Here, in Miss Marsh's twenty-first crime novel, the situation is sillier than usual, the method of murder more improbable, and the tenuous plot will reach only as far as page 254. The prose has a between-the-wars elegance, but if you want a novel about the kind of crime that might conceivably happen, solved by a police- man who approximates more closely to the near thing, the infinitely less well-written Gideon's Risk by J. J. Marric (Hodder and Stoughton, 12s. 6d ) is a roman policier stuffed with incidents a good deal less preposterous than the Marsh- mallow.