IN certain respects the plant alkaloids rank among the most interest ing of naturally occurring substances. For the most part they are of very complex structure, so that the determination of their constitution and the discovery of methods of producing them synthetically ofier attractive problems to the chemist and though a great deal has been accomplished, much still remains to be done in this direction. Their mode of origin and their function in plants are still unknown, and these two questions, with the more important one of correlating the structure of the alkaloids with their physio logical action, form still almost untouched fields for combined work on the part of physiologists and chemists. Many of the alkaloids are of great importance in medicine, and the manufacture of these alkaloids and of products containing them constitutes important branches of the fine chemical industry.