grayson was born in worrall, near sheffield, yorkshire, england, son of joseph grayson, a master cutler, and his wife fanny, "née" smith. grayson came of a family of market gardeners, and travelled to new zealand in the early 1880s. after returning to england and marrying elizabeth clare on 11 august 1886, the couple soon migrated to victoria (australia) where grayson worked as a nursery gardener. becoming interested in science he joined the field naturalists club of victoria, studied botany and did some work on the diatoms, a group of minute plants. grayson attended meetings of the royal microscopical society and developed a talent for preparing microscope slides. before 1894 he had constructed a machine for making micrometer rulings on glass, the results being very good for that time. in 1897 some very beautiful work grayson had done in cutting sections of plants led to his being given a position in the physiology department of the university of melbourne under professor c. j. martin.