Ecological ectocrines in experimental epidemiology. A new class, the "pacifarins," is delineated in the nutritional ecology of mouse salmonellosis.

I have attempted to sketch the ideas forged in a long-term investigation of the possible relationship between host nutrition and resistance to infection. Our endeavor had its origins in the now partially forgotten field of experimental epidemiology, once epitomized in somewhat contrasting schools of thought, English and American. The work of Webster, which showed the importance of host genetic constitution, was an early and decisive influence in the work discussed here, and led to formulation of a new laboratory model of infectious disease, which has been fruitful.