Parasite Invasion, subject of the fifteenth Symposium of the British Society for Parasitology, was well chosen for its timeliness. A high proportion of the references cited were published within five years of the Symposium date, in late October 1976. The contributors to the program likewise were well chosen, as each is a major contributor to the literature in the field reviewed.

The first paper, by P. L. Long and C. A. Spper on Invasion of Host Cells by Coccidia, discusses excystation of Eimeria and Isospora, invasion of cells by Eimeria in vivo, host reactions to invasion by Eimeria, invasion of cells by sporozoites, invasion of cultured cells by merozoites, and invasion of cells by Toxoplasma.

In the second paper, on Invasion of Red Cells by Plasmodium, L. H. Bannister describes the process of invasion, the structure and formation of merozoites, release of merozoites from the schizont, adhesion to new host cells, invasion and transformation of the merozoite into a tropic parasite.