Sir, - With reference to Seamus Heaney's review of Ted Hughes's Birthday Letters (Weekend, January 31st), what in the name of blazes is an "undertruth"? And I am alone in finding the mere two pages you usually devote to book reviews something of an under-allocation, with the limited space disproportionately given over to literature and poets puffing each other's works? - Yours, etc., Sean Murphy,Cliff Road, Windgates, Bray, Co Wicklow