Obituary: Professor H. G. Callan

Harold Garnet Callan, cell biologist: born Maidenhead 5 March 1917; Senior Scientific Officer, ARC, Institute of Animal Genetics, Edinburgh 1946- 50; Professor of Natural History, St Salvator's College, St Andrews 1950- 82 (Emeritus); FRS 1963; Master of United College of St Salvator and St Leonard's 1967-68; author of Lampbrush Chromosomes 1986; married 1944 Amaryllis Dohrn (one son, two daughters); died Dundee 3 November 1993.

H. G. CALLAN was one of the generation of scientists who laid the foundations of modern biology and, having done so, went on to play a leading part in assembling its superstructure. He lived through a golden age of biology when it was possible for individual men and women to carve their names on discrete blocks of scientific progress, using and fashioning the tools that were to become the principal implements of modern science.

'Mick' Callan was born in Maidenhead in 1917 and educated at King's College, Wimbledon, and St John's College, Oxford. He worked briefly at the John Innes Horticultural Institute in Surrey and then received a postgraduate scholarship at the Stazione Zoologica in Naples. While in Naples he met his wife-to- be, Amaryllis, daughter of the Director of the Stazione, Professor Reinhard Dohrn, and he became interested in giant lampbrush chromosomes from animal eggs, a matter that was to occupy him for the next 50 years.

During the Second World War he held a commission in the RAF and became an expert in the application of radar. Afterwards he joined the Institute of Animal Genetics in Edinburgh, which was then directed by the famous developmental biologist CH Waddington. In 1950, Callan was appointed to the Kennedy Chair of Natural History at St Andrews University, succeeding D'Arcy Wentworth Thompson who had held that chair for well over half a century. In the following 32 years he led the Zoology Department at St Andrews into the vanguard of modern biological research and endeavour with a staff who quickly grew to respect and like this frontiersman of 20th-century science.

Of course, Mick Callan did all kinds of other things and was accorded a wide range of honours: election to Fellowship of the Royal Society in 1963, Honorary Member of the American Academy of Arts and Sciences, Foreign Member of the Italian Accademia Nazionale dei Lincei, membership of the UK Advisory Council on Scientific Policy, Trustee of the British Museum and a host of other involvements that reflected a wide respect for his judgement within the international scientific community.

He retired formally in 1982 and, following a short adjustment period, he visited the Carnegie Institution of Washington in Baltimore, as a guest of his long-standing friend Joe Gall. There he immediately became intimately involved in a complex research project that reached right to the very limits of modern biotechnology.

His skills, widely recognised and respected by all who worked alongside him at the bench, were very special indeed. He was in every sense a detective, able to combine extraordinary manual skill, minute attention to detail, strong self-discipline, a keen awareness of the current state of knowledge in his field and the courage to speculate and construct testable hypotheses - and everything coupled with a sense of fun and adventure. It was a constant delight and inspiration to work alongside him.

His work was really all about chromosomes and he made his special mark in science by contributing to our understanding of how chromosomes are constructed and function in their 'lampbrush' form to prepare the unfertilised egg for subsequent development into a complex multicellular organism. Just imagine his background. In his early years in Oxford he was taught by Cyril Darlington, one of the greatest chromosomologists of all time. At the same time he worked alongside the famous cytologist and pioneer of modern cytochemistry John R. Baker, who helped him publish his first paper (1938) in Nature, 'Cell Size in Millipedes'. After the war he worked under Waddington and it was probably then that he became particularly interested in the role of genes and chromosomes in early embryonic development. In 1954 he met and joined forces with a brilliant young American biologist, Joe Gall, and together, in a close working relationship that was to endure to the end of his life, they continued investigating lampbrush chromosomes.

Callan was a teacher. Even at the height of his career, when most professors and heads of departments would have allowed their contact with undergraduates to fall behind research and management responsibilities, Callan maintained an undergraduate commitment that would shock most junior academics in our universities today. He provided a powerful role-model: here was a big man with great personal attractiveness and a sparkling sense of humour who obviously got a tremendous kick out of teaching undergraduates about chromosomes. His former students are to be found today in all parts of the world. Many of them are now highly successful professional biologists. All of them would agree that their lives have been enriched by knowing this man.

Curiously, Mick Callan's success was founded on non-conformity. Today he would be said to have broken most of the rules of modern academic protocol. He worked a nine to six five-day week, always went home for lunch and was never seen in his department during evenings or weekends, which he spent with his fishing rod, his gun, his dog or his friends. He rarely brought science into his home, except to write about it, and he never ever mixed it with his leisure activites. He never searched for postgraduate students or postdoctoral associates. He just let them come to him and even then accepted only the very best into his laboratory. He held few research grants. He published relatively few scientific papers (82) and just one book as a record of nearly 50 years of work.

The secret of his success lies in the quite extraordinary quality and substance of his work. Every paper has a message of timeless significance, set down in a style that is plain, precise and unmistakeably 'Callan'. Every one is a collector's piece. In what remains of his laboratory, the same secret unfolds: comprehensive and meticulous records of his researches and microscope slide preparations every one of which is a veritable work of art. The sadness of his departure is heightened by the instant and irretrievable loss to science and humanity of the skills and experience that would help young people to reach such standards of excellence.

From a strictly personal standpoint Mick Callan was widely known as a man of immense and solid integrity. He was totally and disarmingly straightforward, apolitical and trustworthy in a manner that is, alas, quite rare in modern academic circles. He was married to a truly exceptional woman and those who had the privilege and pleasure of meeting Mick and Amaryllis in their own home will know and have admired the power and stability of this partnership, and it will help them to understand why Mick was such a happy and successful man. He will be warmly remembered for years to come.

(Photograph omitted)