C.J. Villet, generally known as Jean Villet and sometimes as John Villet among English speakers, was a son of Charles M. Villet*, a dealer in natural history material, and his second wife, Amelia J. de Groot. In 1836 he joined his father's business, which then became known as C.M. Villet & Son. They advertised their wares in the South African Commercial Advertiser (e.g., 1 December 1849) and as "Seedsmen and florists" in the Cape of Good Hope almanac and annual register (e.g., 1847, 1857).
Jean Villet made drawings of flowers that were offered for sale through he firm. He also taught drawing at his home in Wale Street. His artistic abilities were developed at an early age, for on 15 December 1835, when he was eighteen, Sir John Herschel* wrote in his diary that Mrs Hawkins, who visited him that day, had "brought a lot of flower-paintings of Villet" (Evans et al, 1969, pp. 202-203). It seems that he did not sign his work, with the result that the only known flower painting that can be attributed to him with certainty is that of Orothamus zeyheri, a member of the Protea family. The plant was discovered by C.L.P. Zeyher*, who took Villet's painting of it to Kew Gardens in 1844. The painting was published in Curtis's Botanical Magazine in 1848.
On 7 December 1841 Villet married Johanna H.C. Klerck in Cape Town. After her death in 1866 he married his second wife, Jacomina (or Jacoba) C. du Plessis, in Cape Town in December 1869. His only son (from the second marriage) was named Charles Mathurin, after the grandfather.
Jean, under the name John Villet, was listed as an annual subscriber to the Cape Town Botanic Garden in the South African Commercial Advertiser in 1849. He continued his father's business for some time after the latter's death in 1856, but moved it to his house in Wale Street. Around this time he again became known by his given names, Carolus Johannes.