Abstract
In the Letter to the Editor by F. Roels entitled "Cytochrome c and Cytochrome Oxidase in Diaminobenzidine Staining of Mitochondria," which appeared in the June issue of the Journal (Vol. 22, pp. 442-444, 1974), the text, where it is carried over from page 442 to page 444, should read, "The thesis that DAB reacts with cytochrome c also implies that the addition of cytochrome c to the medium carries some risk of provoking precipitates in locations where endogenous cytochrome is absent."