The more mechanical methods of microencapsulation are represented by two techniques, one involving a fluidized bed the other involving mainly a centrifugal method. Baxter of Moore Business Forms, studied capsules made by mechanical methods as well as by chemical methods.

of McGill University of Montreal, Canada, who talks about artifi­ cial cells prepared from semipermeable microcapsules. Also illustrative of this method is a contribution on microencapsulated pesticides by C. B. Desavigny and E. E. Ivy of Pennwalt Corporation. Another method of polymerization in situ is micro­ encapsulation by vapor deposition, the subject of W. M. Jayne of Union Carbide Corporation. The more mechanical methods of microencapsulation are represented by two techniques, one involving a fluidized bed the other involving mainly a centrifugal method. The fluidized bed method is covered in a paper by H. Hall and T. M. Hinkes of the Wisconsin Alumini Research Foundation. The centrifugal and other related methods are treated by Mr. J. E. Goodwin and Mr. Sommerville of the Southwest Research Institute of San Antoni~ Texas. Dr. G. Baxter of Moore Business Forms, studied capsules made by mechanical methods as well as by chemical methods. Mr. Russell G. Arnold of the Bureau of Veteranary Medicine of the Food and Drug Administration draws our attention to the procedures to be used for securing approval of a new animal drug application for the marketing of microencapsulated products. And last but not least, we have a contribution by Mr. G. O. Fanger on "Micro­ encapsulation a Brief History and Introduction, whose title speaks for itself.