Mortality from Lymphomatosis and Other Causes Among Inbred Lines of White Leghorns

THIS report presents data collected over a nine-year period on resistance and susceptibility to lymphomatosis among six different inbred lines of White Leghorn chickens maintained at the Regional Poultry Research Laboratory at East Lansing, Michigan. Waters (1945) presented data which included the behavior of these six inbred lines, together with nine other lines, for 1939 to 1943 inclusive. In addition to mortality from lymphomatosis, this report gives consideration to all other mortality occurring among the six inbred lines. In nearly all, if not all, experiments with living organisms, the investigator must contend not only with mortality resulting from the specific disease under consideration but also with mortality from a multiplicity of causes. Thus, when dealing with death from a specific disease as it occurs in a group of chickens, one should also give consideration to the aggregate of other reasons for death in this same group of chickens. It becomes . . .