This volume is the fourth in a series on depressive illness. The first volume, entitled Phenomenology of Depressive Illness, is devoted to a de scription of depressive illness from a variety of perspectives that include that of the patient, the clinician, and the psychiatric researcher. It de scribes the major subtypes of depressive illness and places them in the context of the life cycle. The second volume in this series is entitled Models of Depres sive Disorders: Psychological, Biological, and Genetic Perspectives. This volume describes several major models of depressive disorders, in...

A world of categones devmd of spirit waits for life to return. Saul Bellow, Humboldt's Gift The stock-in-trade of communicating hypotheses about the historical path of evolution is a graphical representation called a phylogenetic tree. In most such graphics, pairs of branches diverge from other branches, successively marching across abstract time toward the present. To each branch is tied a tag with a name, a binominal symbol that functions as does the name given to an individual human being. On phylogenetic trees the names symbolize species. What exactly do these names signify? What kind of...