The botanical sources of the sundry intoxicating snuffs of the New World tropics has long been uncertain or, in some instances, unknown. One of the most recently identified snuffs, prepared from the resin of various species of the myristicaceous genus Virola and employed by a number of Indian tribes in the northwestern part of the Amazon, is now relatively well understood as a result of interdisciplinary investigations of the past thirteen years. It seems to be an appropriate time to appraise and integrate the numerous reports concerning the botanical ingre dients of the myristicaceous snuffs and to summarize what we now know about this problem. It would appear, further more, an advantageous opportunity to offer such a summary, in view of current interest in the phytochemistry and pharmacology of the resin of Virola and related genera. This paper is the second in a series dedicated to the study of poisonous plants of the New World tropics. The first paper in this series was published in the Botanical Museum Leaflets, Harvard University 21 (1967) 265-28. Part of the research reported in this paper was supported by the National Science Foundation through the R. V. Alpha Helix of the Scripps Oceanographic Institute in La Jolla, California. The authors were invited to participate in Phase C. of the Alpha Helix Amazon Expédition in 1967, under the direction of Prof. Carroll M. Williams of Harvard University. During July and August, we were able, as members of this team, to devote special attention to the myristicaceous snuffs of several groups of Waikâ Indians of the Brazilian territory north of the Rio Negro. We were able, also, to begin phytochemical examination of a number of species of Virola and related genera. Our studies on the snuffs encompassed botanical, ethnobotanical, phytochemical and toxicological investigations and, viewed and interpreted against a background of what has previously been done, seem to lay a foundation for more intensive and extensive research along sundry avenues. Having the excellent laboratory facilities of this ship so near the scene of our field studies made it possible to carry out chemical observations that might have been out of the question in laboratories as far away as Europe or the United States. Detailed results of the phytochemical investigations will be published in a subsequent paper.