First published in 1977, this volume is a short and integrated account of the dynamic mechanisms involved in the defence of plant cells against attack by parasitic bacteria and fungi. The central interest of the volume is with the processes by which plant cells perceive the approach of an intruder and occasionally permit, but usually discourage, its further progress. How do the genes of host and parasite communicate to determine the outcome of attempted parasitism? Is there a universal defence mechanism in all plants and, if so, what is it? What contribution does the much studied process of phytoalexin formation make to the defence of plants? These are the main questions considered by Professor Deverall, and they are approached from a basis of our understanding of the genetical, cytological and biochemical interactions between plants and parasites. Plant pathologists, mycologists, botanists, microbiologists, plant physiologists and plant biochemists who are professionally concerned with plant disease will find that this monograph reviews past advances in an area that was once the subject of much attention, and provides suggestions for solving some of the problems.

Insects counteract infection by a variety of reactions, partly humoral but principally cellular. This monograph considers their cellular reactions, especially the phagocytosis of micro-organisms and the encapsulation of larger parasites, from two main points of view: parasitological and cytologica. The first aspect involves description of the reactions and of their effects on parasites. This part of the subject is basic to the biological control of insect pests, because a better understanding of cellular defence reactions could lead to improved methods of using insect parasites to human advantage. The second aspect involves analysis of the stimuli that evoke cellular reactions. This part of the monograph attempts to relate the defensive activities of insect blood cells to general problems of cytology, such as the recognition of foreign bodies, the aggregation of cells and their adhesion to foreign surfaces and their extreme flattening on each other as they form capsules. Two final chapters discuss the efficiency and specificity of insect defence mechanisms and compare them with the immunity reactions of vertebrates.