A review of the cyto-logical features of glandular secretion as Bowen thought of them shortly before his death. This article deals with the historical development of the problem, the individual cell as the basis of glandular activity, the morphological basis of secretion, the secretory cycle, the origin of secretory droplets, and the role of the nucleus in secretion. The gland-cells produce characteristic substances by means of chemical transformations. The term"secretion" is, for the cytologist, confined to the process of intracellular synthesis. The morphological basis of secretion is believed to be adequately founded upon vacuolar formations of duplex structure. Problems of glandular cytology center about the question of the origin of individual secretory droplets. The role of the nucleus in secretion is thoroughly reviewed in the light of evidence presented by studies of nuclear shape, size, position, and staining capacity. Visible secretory materials produced by the nucleus originate (1) from nuclear substances of indeterminate identification, (2) directly or indirectly from nucleoli, (3) from the chro-matin (chromidia, etc.), and (4) from the nebenkern. In a critique of nuclear function in secretion, it is concluded that the nucleus is not the immediate source of secretions. "Secretion is a function in which all parts of the cell may very probably be called upon for their contribution toward the end result, and in this process the nucleus seems to do its bit.".