Massart and Bordet, Leber, Metchnikoff and others have studied the phenomenon in leucocytes, with the result that while there is evidence of their being positively chemiotactic to the toxins of many pathogenic microbes, it is also apparent that they are negatively influenced by such substances as lactic acid.
Ersten Entwicklungsphasen einiger Cynipidengallen (Amsterdam, 1882); Bordet, " Phagocytosis," Ann.
Ii.; Marshall Ward, Timber and some of its Diseases (London, 1889); Massart and Bordet, " Irritability of Leucocytes," Journ.
Still another view, advocated by Bordet, is that the union of toxin and antitoxin is rather of physical than of strictly chemical nature, and represents an interaction of colloidal substances, a sort of molecular deposition by which the smaller toxin molecule becomes entangled in the larger molecule of antitoxin.
Metchnikoff and Bordet subsequently devised means by which a similar change could be produced in vitro, and analysed the conditions necessary for its occurrence.
The former (Immunko y per of Ehrlich, substance sensibilisatrice of Bordet) is the more stable, resisting a temperature of 60° C., and though giving the specific character to the reaction cannot act alone.
Red corpuscles (Bordet, Ehrlich and Morgenroth), leucocytes and spermatozoa (Metchnikoff).