MR. EDWARD HERON-ALLEN is to be congratulated on the interesting results which are rewarding his assiduous study of the Foraminifera. His latest contribution (Phil. Trans., June, 1915) deals with the processes of reproduction and of shell-making. In addition to the production of zoospores observedby Lister and others, some species exhibit viviparous reproduction and the budding-off of young individuals. The viviparous young are formed inside the parent shell and emerge by the dissolution of the base. The process demands a sacrifice of the whole of the protoplasm and of the internal septa, whereas in zoosporeproduction the shells of the young are formed outside the parent, from material derived from the surrounding medium, and not from the internal septa. Another method of multiplication is to bud-off a young individual from the shell-aperture of the parent. To this process and to the occasional (possibly fortuitous) mingling of the extruded protoplasm of two or more shells, is generally attributable what has been described as “plastogamy” in the Foraminifera.