Gave rise to a selection process in which the survivors were predominantly those with greater capacity to retain sodium in their system, while those with lower capacity perished. The selection mechanism was dehydration. Wilson and Grim hold that the black populations that grew out of the slave imports came to be dominated, through genetic inheritance, by people with extra capacity to retain salt in their system. And this, they conclude, is the main factor that explains the phenomenon in question. This explanation is disputed by other medical scientists. The conflicting views of the contending scientists were summarized recently by Daniel Goleman (1990). According to Goleman, Elijah Saunders, a cardiologist at the University of Maryland Medical School and coauthor of a leading textbook on the subject, Hypertension in Blacks, holds that anger against racism is the principal cause of hypertension among blacks in the United States. Shirley Brown of the University