First scientific director of the Singapore Botanic Gardens (Nov 1888 - Feb 1912)

'The name Ridley is a symbol of an intangible trust of scholarship and learning from which both the spiritual and material progress of a country is deriving its strength'

- The Minister for Economic Affairs in the Federation of Malaya (circa 1955)

'Few people have accomplished so much in twenty-three years of tropical service or have completed their work as he has done on retirement.' ... 'His gargantuan contribution to our knowledge in most branches of natural science in Malaya and his application of it to economic problems and crop production is as astonishing as his longevity. Had Ridley commercialised his knowledge he could have made a fortune. Others made the fortunes because of his work, but his scientific studies and his discoveries were more important to him than riches.'

- Biographical Notes, The Ridley Centenary, 1955.