AdetECTIVE friend of Dr Mary Noble affectionately refers to her as ``Miss Marple''. It's easy to see why. Seated bird-like, in her book-lined sitting room in Bonnyrigg, Noble fixes you with beady eyes which belie her 85 years; while the mental astuteness, intelligent face, sensible tweed skirt and crisp blouse all suggest she may be poised to spring purposefully from her chair, happy to have solved some convoluted case in her head. Throughout professional life and into retirement, Noble has pursued her hunches with a doggedness worthy of any fictional sleuth.

It comes as no surprise, therefore, to learn that during 34 years as a seed pathologist for the Department of Agriculture for Scotland, Mary Noble rejoiced in the nickname ``bonny fechter''. Recruited to the government's East Craigs laboratories in 1937, she was one of the UK's first plant pathologists in what was the first official seed testing station north of the Border. Lone female in a new and male dominated field, she had to earn respect. ``The official government seed testing people often told me I was wrong, without the evidence to back it up. But I knew when I was right - I used to have to stick to my guns.''

Distinguished service as travelling ambassador for the International Seed Testing Association and pioneering work in seed pathology earned Noble the Imperial Service Order. At East Craigs, a lab is named after her, and she is a Fellow of the Royal Society of Edinburgh.

Mary Noble is also a past vice president of the British Mycological Society, a body dedicated to the study of fungi which is celebrating its centenary this year. Following a BSc in Botany, Noble won a Carnegie Research Scholarship to embark on a PhD in Mycology, focusing on fungi which cause plant disease. At this time, her life started to parallel that of a woman Noble regards as a kindred spirit: Beatrix Potter. ``To study a certain phenomenon, I had to grow fungi spores and I realised that, 100 years before, Potter had been the first person to germinate spores from this particular group, toadstools.''

Often dismissed simply as the author of the Peter Rabbit books, Potter in fact was a distinguished mycologist. Self-taught, she pioneered the use of the microscope and ultimately knew more than the academics at Kew. In 1897, she submitted her paper on fungi germination to the Linnaean Society (after the Swedish botanist Linnaeus), which made public only the title of her work. Her germination claims were refuted, prompting Potter to record in her diary (decoded only in 1966): ``It is odious to a shy person to be snubbed as conceited, especially when the shy person happens to be right''.

Next year, Professor Roy Watling, Principal Mycologist at the Royal Botanic Garden, Edinburgh, is to deliver a lecture to the Linnaean Society on Beatrix Potter's research on the 100th anniversary of her rejection - an act of official contrition.

Mary Noble's links with Beatrix Potter extend further than academic research, however. Daughter of a chemist in Leith, Noble was made aware at an early age of the medicinal properties of plants. Between the ages of nine and 19, she holidayed every August with her family in Kingussie (``I noticed there were plants in the Highlands which I couldn't find on Arthur's Seat.'') Potter, on the other hand, holidayed between the ages of four and 15 in country mansions in Perthshire - Dalguise, Eastwood (where she created the character of Peter Rabbit in 1893 and wrote the Tale of Jeremy Fisher) and Birnam. Denied this experience, Potter would never have met local postman Charles McIntosh, an amateur mycologist well known to Perthshire Natural History Society. It was not until 1892, when Potter was 26 and McIntosh was retired, that the pair's interest in fungi sparked a collaboration which allowed the London-based writer/ illustrator to study specimens from the Perthshire area -courtesy of Her Majesty's post.

Mary Noble's detective work unearthed a some years ago a cache of correspondence between McIntosh and Potter which had never seen the light of day. Noble - a member of the Beatrix Potter Society who attributes her own passion for plants to an inspirational botany teacher at the Mary Erskine School - describes the discovery in her book, A Victorian Naturalist. ``Through friends, I met up with Charlie's niece in Dunkeld,'' Noble says. ``In 1972, Miss McIntosh gave me a parcel of letters . . .''

The fin

Scottish connections with the Lakeland artist are more numerous than at first realised. Potter's painter/farmer brother Bertram, for instance, lies buried in Ancrum churchyard, having married a girl from Hawick (the Beatrix Potter Society has marked his gravestone with his provenance); and one of the earliest artistic influences on Beatrix was Jemima Blackburn, Highland author of Birds Drawn From Nature. Daughter of one of the Clerks of Penicuik and widely recognised as the prototype for Jemima Puddleduck, Jemima was related to the Potters. Beatrix received the bird book on her tenth birthday and was pleased to meet Mrs Blackburn in person in 1891. Another influence was painter John Everett Millais, a family friend who often holidayed at Dalguise, (Millais pere said what his son and Beatrix shared was ``observation''.)

This year, Mary Noble's expertise has been in much demand. Despite the fact she is waiting, in some discomfort, for an abdominal and a cataract operation, she was guest lecturer this summer at the seventh international conference of the Beatrix Potter Society. Her subject was Potter the Mycologist, and she used exhibition material prepared, under her guidance by Professor Watling. Noble describes him as her ``mycological guru''; he, in turn, says he has helped interpret Beatrix Potter's work. The stand is one of four Royal Botanic Society exhibits from Edinburgh designed specifically for Fungus 100, an event in September which marked the centenary of the British Mycological Society.

Copies of some of Potter's fungi pictures hang in Dr Noble's hall. A Peter Rabbit biscuit tin sits on the tea tray, and a soft toy version of the character lies on the bookshelves (``friends of the Royal Botanic Garden gave me him on my 80th birthday''). There is a shelf devoted entirely to books on Potter, including a rare biography of Charles McIntosh published in 1922 after his death.

Mary Noble's professional life took her all over the world - following retirement from the Department of Agriculture, she was invited to work for the Danish government, teaching seed pathology to developing countries. Yet one suspects she is happiest immersed in subjects nearer to home - her love of mycology and Beatrix Potter and related interests which include local history, photography and gardening. ``We're still working on Beatrix's drawings and finding she was more right than she knew,'' points out Noble. ``Fungi are such mysterious things. New technology is helping us discover what no- one has seen before.''