Effects of Secretions

Abstract

SOME secretions of some organisms found to be inimical to some metabolic step necessary to the normal processes of some other organisms have come to be referred to as 'antibiotics'^1,2. As has been pointed out by Lucas³, it seems likely that it will be found profitable to regard such secretions as special cases of that great class of substances, distinguished by being physiologically active, the study of which constitutes a large branch of comparative physiology, and to consider their effects in terms of the evolution, by natural selection, of the organisms concerned. Their adverse effects on some organisms are presumably an example of these organisms not being adapted in a particular respect, comparable, in principle, with many other examples in ecology.