Volume 10 of this series presents four timely reviews. Chapter 1 provides a fascinating account of the history of alkaloid discovery in Australia beginning with the isolation of the first alkaloid from an Australian plant, the Tasmanian sassafras <IT>(Atherosperma moschatum),</IT> by Zeyer in 1861. Also included is a comprehensive survey of alkaloid-bearing plants, and a section dealing with detection, estimation, extraction, and work-up procedures for alkaloids.<P>Chapter 2 provides a comprehensive update to the chapter on "Pyridine and Piperidine Alkaloids" which appeared in volume 3 of this series. The focus of this chapter is on new alkaloids isolated, biosynthesis, and biological properties.<P>Chapter 3 looks at "3-Alkylpiperidine Alkaloids Isolated from Marine Sponges in the Order Haplosclerida". Studies over the past thirty years have shown that sponges are a rich source of alkaloids. Many of these sponge alkaloids are related to each other by the presence of a 3-alkylpiperidine moiety in their structures and it happens that the sponges that have been reported to contain 3-alkylpiperidine alkaloids are all in the order Haplosclerida.<P>Chapter 4 reviews &bgr;-carboline and isoquinoline alkaloids which are pharmacologically some of the most significant marine natural products. This chapter treats the isolation, structure elucidation, synthesis, biosynthesis, and pharmacological activity of these alkaloids.