My last paper on the “Theory of Circulants” appeared four years ago (Proc. Roy. Soc. Edin., xxxii, pp. 136–149), and brought up the history of the subject to 1880. I have now completed the research up to the close of the nineteenth century—the goal originally aimed at. It is considered that from the beginning of the present century the indexing of mathematical writings is sufficiently full and detailed to make it comparatively easy for a worker to follow up for himself the recent lines of development.