The biology of senescence

2 Number of survivors out of 100,000 born alive, for each race by sex: United States, 1939-41 3 Number of Survivors out of 100,000 male live births, from recent life-tables for selected countries 4 Frequency distribution of ages at death in a cohort starting with 100,000 live births, based on the mortality of white males: United States, 1939-41 5 (a) Survival curve at a constant rate of mortality (b) Survival curve of a population which exhibits senescence(definition) 6 Types of survival curve 7 Survival curves of a German population 8 Survival curves for cafeteria tumblers 9 African Ibis (Threskiornis aethiopicus) . Survival of 21 indi- viduals Night Heron (Nycticorax nycticorax). Survival of 17 indi- viduals 10 Orkney Vole (Microtus orcadensis) . Survival of 24 individuals 11 Patagonian Cavy (Dolichotis patagona). Survival of 55 individuals 12 Mouflon Sheep (Ovis musimon). Survival of 77 individuals 13 Irish Wolfhounds. Survival of 67 individuals from 12 months of age-sexes combined 14