[From The Quest for the Rose, by Phillips & Rix, p. 132:] James Cocker & Sons of Aberdeen was founded in 1841, soon after James Cocker left his job as gardener at Castle Fraser following a disagreement with his employer, who had told him to pick fruit for the house on the sabbath. Rose breeding began in the 1890s and the company's first important rose was 'Mrs. Cocker' (1899). The business closed in 1923 soon after the early death of Alexander Cocker, the founder's grandson, but in 1936, it was revived by Alexander's son, Alec Cocker [which see], as a general nursery.

[From The Makers of Heavenly Roses, by Jack Harkness, pp. 150-159:] The Cocker nursery began in 1841... a small nursery in the Sunnypark district of Aberdeen... By the time James the founder died... his firm had taken on more ground nearby at Morningfield, and had leased a shop as a seed warehouse at 82 Union Street, the city's main shopping street... The second James Cocker had three sons, William, a third James, and Alexander. All three were brought into the business... the firm became in 1882 James Cocker & Sons... Alexander, having survived his two brothers in the business, eventually became the sole proprietor... Their first [rose] varieties, brought out in 1892, were two chance sports from Hybrid Perpetuals ('Duke of Fife' and 'Duchess of Fife')... [Alexander died in 1920 and the trustees appointed to attend to the affairs of his children, Margaret and Alexander Morison ("Alec"), closed the nursery in 1923]

[From Roll Call: The Old Rose Breeder, p. 88:]
[James] Cocker & Sons
Aberdeen, Scotland
James Cocker, 1831-1897
Sons:
Alexander
James
William