Colouring Matter contained in the Seed-coats of Abrus precatorius.

The toxic principle contained in the seeds of Abrus precatorius has been the subject of elaborate investigations by many workers, including Klein, De Wecker, Sattler, Warden, Waddell etc. But it appears that none has thought it worth his while to investigate the chemical nature or the properties of the colouring matters contained in the coatings of the seeds of Abrus precatorius. Dr D. D. Cunningham, however, has given a description of the microscopical structure of the seeds of Abrus precatorius [1882], which I quote below so that the description may be recorded in a journal which is readily available for reference. " The integument of the seed consists of no less than nine distinct layers of cells differing considerably from one another in their characters. Proceeding from without inwards we find: (1) A layer of considerable thickness but containing only a single stratum of cells. They are thick-walled, columnar cells containing the colouring matter to which the seed owes its bright scarlet hue, and are arranged in radiant fashion around the deeper portions of the integument. Each cell is dilated peripherally and in many cases a slight basal bulbosity is also present. The peripheral dilated portion is cut up into a number of more or less cuneate portions which are closely adapted to one another. In many cases in the mature seeds the central point where the apices of the segment come into relation to one another really consist of a narrow canal leading directly into the cell-cavity. The surface of the seedcoat due to the close apposition of the cells, necessarily comes to present the appearance of being composed of a layer of cuneate facets arranged in rosetted fashion around central points-each rosette representing the extremity of one of the columnar cells, and the central points in many instances being openings, leading directly into the cell-cavities.