The influence of natural selection on the incidence of leprosy

ABSTRACT

1- By appeal to the laws of natural selection and application of the herd experiments of Topley and Wilson it has been shown that natural resistance is necessarily raised by leprosy through the elimination of the great majority of susceptibles in an infected race. 2- The behavior of leprosy in this respect has been shown to be analogous to that of other diseases, like measles and tuberculosis. 3- it has been shown that natural resistance supplies an explanation for otherwise anomalous events in the history of leprosy, events that cannot be explained satisfactorily by any other hypothesis unless it be admitted that natural selection is also in operation. 4- Natural selection was probably the dominating influence in determining the present freedon of Europe from leprosy.