Sir, - Gavin Tobin (March 29th) refers to the prevalence of "Mum" rather than "Mammy" in radio commercials. In the early 1970s, when a group of researchers from English universities were in Ireland studying blood groups, they couldn't understand why in one small country village most children called their mothers "Ma" or "Mammy" while a small but significant group called their mothers "Mum" or "Mummy". On asking the local GP they were given a simple answer. The "Ma/Mammy" group were Roman Catholic and the "Mum/Mummy" group were Church of Ireland. I know this because my father was the GP in question. - Yours, etc.,
John F. Doyle, Mill Road, Midleton, Co Cork.