A light microscope study was made of ovule development in Brassica catnpestris L. cv. Candle (canola, rapeseed), from the initiation of the ovule to the mature megagametophyte. The ovule is bitegmic and campylotropous and exhibits the Polygonum-type of megagametophyte development. The inner integument is dermal in origin from a series of wedge-shaped initials. The outer integument is derived from both dermal and subdermal initials that originate proximal to the inner integument. The megasporocyte arises from an archesporial or primary sporogenous cell. The products of meiosis are a triad or tetrad of megaspores. Expansion of the megagametophyte is micropylar and coincides with the formation of a large central vacuole. The mature binucleate central cell is devoid of the large central vacuole characteristic of the coenocytic and early cellular stages of megagametophyte development. The cell walls of the mature egg apparatus and antipodals are periodic acid – Schiff positive. The antipodals, unlike the cells of the egg apparatus, do not increase in size following their formation.