This volume begins with Ivan Good body's review - the first in this field - of work on the physiology of ascidians or sea squirts, among the commonest but, physiologically, one of the most obscure groups of marine animals. The second article - another first review in an almost completely neglected field - is by the late L. E. Mawdesley-Thomas and deals with pathological growths or neoplasia in marine animals from the few recorded in invertebrates to the more numerous cases in fish and marine mammals. It is hoped that this may stimulate further enquiry. Of recent year's shrimps, particularly the tropical penaeids, have become, economically, one of the most important groups of marine mammals. Makoto Omori here deals at length with all aspects of the biology of deep and mid-water shrimps, all of which constitute essential links in the economy of marine life. The processes of life are rhythmical and, in the last chapter, Alain Sournia cites instances of circadian periodicities in the populations of marine plant plankton, a matter of fundamental importance as this phytoplankton represents the great bulk of primary productivity in the sea.

The first article of volume 8 is on paniculate matter present in the sea in the form of detritus and minute particles of organic matter. The possible part played by such material in the nutrient cycle of the sea is discussed. The second article gives an account of fish and prawn farming in brackish water ponds and in estuaries. Another article of contemporary interest supplies a balanced review of the causes and results of oil pollution. This supplies background information not generally available to the biologist and a comprehensive bibliography. The final contribution is on the faecal pellets of many bivalve molluscs, which form a significant part of the material in muds and supply nutrient matter to deposit feeders. A knowledge of their structure helps in the study of mollusc evolution.