Born in South India, 25 October 1879, second child and only son of Cumarasingham Murugesapillai, a deputy collector in Tanjore, and Seethalakahmi Clarke, his wife. He was educated at the Hindu High School, Triplicane, Madras, and at the Presidency College, Madras. He came to England and took the Conjoint qualification in 1908 and the Fellowship in 1910. At that time he spelled his name Kumarasamy and it so appears in the College books. For the rest of his life Cumarasamy practised in Ceylon, latterly at Maligakande, Maradana. From 1909 to 1911 he was lecturer in anatomy at the Ceylon Medical College, Colombo. He occasionally acted as third physician at the General Hospital, Colombo, and was for a time medical superintendent of the Colombo lying-in hospital. He married (1) in 1900, Subramaniam Balambali, and (2) Saravanamuttu Sellamma, and left four sons and seven daughters. He died in Ceylon on 13 June 1941.