Percy Sladen (1849-1900)

Walter Percy Sladen, known as Percy, was the son of a wealthy merchant from Halifax. His interest in echinoderms (starfish, sea urchins and related creatures) awoke during trips to the Yorkshire coast while he was still a young man. Later he toured most of the major European museums and spent several months studying preserved specimens. He also observed live animals at the Zoological Station in Naples. In 1898 Sladen and his wife Constance moved to Northbrook Estate in Exeter because he was in poor health.

Sladen gathered a large collection of specimens during his lifetime. It includes microscope slides from Dr William Carpenter and fossils from Professor PM Duncan. Carpenter trained as a medical doctor and as part of his training he studied a wide variety of life forms. He prepared microscope slides of their organs and tissues in order to prepare himself for a better understanding of the functioning of the human body.

Sladen died in Florence in 1900. In 1903 Constance presented his collection to RAMM. She paid for the ‘Sladen’s Study’ gallery to be created in his memory and for a curator to research and display her husband’s collection. This collection is the largest and most comprehensive echinoderm collection outside the Natural History Museum, London.

Percy Sladen and HMS Challenger

Sladen’s reputation brought him to the attention of Scottish scientist Sir Charles Wyville Thomson. Thompson was looking for someone to describe the starfish specimens collected on the Voyage of HMS Challenger (1872-76). This 70,000 nautical mile voyage of exploration laid the foundations for almost every branch of ocean science we know today. Sladen wrote nearly 1,000 pages describing the starfish and made 118 illustrations. These are part of the final 50-volume (30,000 page) report. Museums all over the world have specimens from HMS Challenger – explore their collections on RAMM’s website.


Percy married Constance Anderson in 1890. Their relationship was, ‘a union of heart and mind, yielding a bright and tender sympathy which strengthened and stimulated him in his life’s work’. Constance was a talented artist. She exhibited works in London galleries. She was also an authority on the archaeology of Yorkshire.

Constance was one of the first women elected as a Fellow of the Linnean Society in 1904/5.

In addition to her generosity towards RAMM, she gave money to many local charities. She also set up a trust in her husband’s memory. The Percy Sladen Memorial Fund still exists today. It gives grants to fund travel for research in biological and earth sciences. As recognition of her ‘enlightened method of commemorating [his] memory’ a new species was named after her. Mr Oldfield Thomas called it the pale-bellied woolly mouse-opossum (Micoureus constantiae).

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