Stella Madeline Davies, 1927 - 2008

By Elizabeth Platts and Richard C. Preece

Extracted from Journal of Conchology, Volume 40, pp. 111–112.

Stella, born on the 9th. January 1927 in Croydon, Surrey, was the youngest daughter of the eminent geologist George MacDonald Davies. His first wife had died leaving him with one daughter, Margaret, and subsequently his second wife, Agnes, gave birth to John Grant Davies (the astronomer) and Stella Madeline Davies.

In 1932 the family moved to a house in Sanderstead, Surrey where, after the death of their parents, Stella and her sister Margaret continued to live until they moved into a retirement home in 2005. Stella attended Croydon High School for Girls (GPDST) and went with the school to Bradden in Northamptonshire when it was evacuated during the Second World War. After finishing her schooling Stella went up to Cambridge where she studied Natural Sciences at Girton College.

After university Stella worked in the Natural History Museum, London, as an assistant in the Zoology Department. She joined in January 1948 and worked in the Annelid section, with Maurice Burton and Norman Tebble, leaving in April 1951. Stella then had a teaching job in Yorkshire. At one period Stella rode a motorcycle, but she never drove a car. In later life she once said that she was too nervous to drive a car, but would have enjoyed the freedom it could have given her.

For many years Stella worked at St Margaret’s, a school in Croydon for children with cerebral palsy, where she was a house parent. She was particularly involved with caring for the physical needs of the children rather than with the teaching side of the school and she stayed in touch with some of the children until her death. She also helped with the Winged Fellowship Trust, now renamed Vitalise, a charity providing holidays for disabled people, and continued to accompany groups until she was in her seventies. She was held in great affection by the Trust and news of her death caused much sadness.

Stella was a longstanding member of both the Malacological Society of London and the Conchological Society of Great Britain and Ireland. Stella herself was internationally renowned as a specialist in the biology of slugs. She was generous in her help to other workers on slugs, particularly those in continental Europe. As a leading expert, she regularly received parcels in the post containing slugs. Not all specimens arrived in perfect condition prompting her to write an article about precisely how this should be done for the benefit of all concerned (Davies, 1994). Her generally quiet demeanour would become animated and forthright when discussing her favourite animals, which she regularly brought to meetings to show the extent of variation that occurred in siblings. She was a keen observer with a sharp eye, as the following two examples illustrate. Reversed coiling is easy to detect in gastropods with coiled shells but there are very few records of sinistrality in slugs, Stella reporting two (Arion intermedius and Milax gagates) of the five known specimens (Reise et al. 2002). The phenomenon is obviously more common than supposed but it requires someone with Stella’s eye to detect it. The second example, and the one for which she is best known, concerns her meticulous observations of the behaviour and ecology of slugs in her garden in Croydon (and elsewhere) made over many years. In order to resolve the identity of several variable forms of slug, she undertook long-term breeding experiments, which led her to conclude that one of our most common horticultural pests, Arion hortensis, was actually an aggregate of three distinct species, one of which she described as new to science (A. owenii). The validity of these conclusions has now been supported by recent molecular techniques (e.g. Backlejau, 1987). Her views on the taxonomy of closely related species of slug were ahead of her time.

As a colleague commented “What was impressive was the way in which she related her detailed, original work on the genital anatomy of Arion with equally original observations on the breeding cycles of the different taxa that she established. This came from the most careful recording over many years, in her garden and elsewhere – natural history in the best sense.” However, “getting her to publish [her findings] was quite another matter... extracting manuscripts from her was a real struggle, and then she would insist on having them back for rewriting and refining. It is a pity that her perfectionism did not allow her to publish more, especially on the larger Arion species.”

Apart from her interest in natural history Stella also had a keen interest in family history. Amongst her papers were a number of trees for different branches of the family and her niece, Kate, has taken these over to continue Stella’s interest in genealogy. For someone of her generation she was also very aware of ecological issues and this was well known within her family. Her brother John’s son and daughter, Richard and Kate, wrote: “She would talk about water use in the SE of England and the need to use energy sparingly etc. Her interest in the water cycle in the SE is no doubt related to her father’s professional interest in the subject; he was a geologist and I believe he wrote a paper on the subject. In the residential home she would regularly complain about the wasteful use of resources. This was of course after 2005. But she recycled as much as possible for as long as [any] other family members can remember.”

Stella was a shy, unique and somewhat eccentric person, but she was much loved and respected by her family, friends and her many malacological colleagues. Her natural history papers were left to the Conchological Society of Great Britain and Ireland, together with a legacy of £2000 and her collection of slugs were passed on to Dr Roy Anderson, as she had requested.

In preparing this obituary, we acknowledge the help of Richard and Kate Davies, Thierry Backlejau, Nick Evans, Michael Kerney, and John Peake.


BACKLEJAU T 1987 Electrophoretic distinction between Arion hortensis, A. distinctus and A. owenii (Mollusca: Pulmonata). Zoologischer Anzeiger 219: 33–39.
DAVIES SM 1994 Slugs by mail. Conchologists’ Newsletter 128: 303—304.
REISE H, BENKE M & HUTCHINSON JMC 2002 A sinistral specimen of the terrestrial slug Arion lusitanicus (Gastropoda: Pulmonata: Arionidae). Malakoligische Abhandlungen Staatliches Museum für Tienkunde Dresden 20: 247–252.



List of publications

DAVIES SM 1972a Sinistral Arion intermedius. Conchologists’ Newsletter No.40 : 251.
DAVIES SM 1972b Field Meeting at Highgate Cemetery. Conchologists’ Newsletter No.43: 293–295.
DAVIES SM 1973a Slug or snail? Conchologists’ Newsletter No.44: 296.
DAVIES SM 1973b Another sinistral slug – Milax gagates (Drapamaud). Conchologists’ Newsletter No.45: 318.
DAVIES SM 1977 The Arion hortensis complex, with notes on A. intermedius Normand (Pulmonata: Arionidae). Journal of Conchology 29: 173–187.
DAVIES SM 1979 Segregates of the Arion hortensis complex (Pulmonata: Arionidae), with description of a new species, Arion owenii. Journal of Conchology 30: 123–127.
DAVIES SM 1987 Arion flagellus Collinge and A. lusitanicus Mabille in the British Isles: a morphological, biological and taxonomic investigation. Journal of Conchology 32: 339–354.
1988 An albumen gland protein polymorphism in the terrestrial slug Arion owenii. Biochemical Systematics and Ecology 16: 425–429.
DAVIES  SM 1994 Slugs by mail. Conchologists’ Newsletter No.128: 303–304.