“…An exception is N,N'-2,7-fluorenylenebisacetamide, which has a special effect on the glandular stomach of rats and mice, besides its usual carcinogenic activity (Morris et al, 1962;Stewart et al, 1961;. The introduction of other carcinogens into the wall of the stomach has also appeared ineffective, and only in exceptional cases (Solovyov et al, 1963) have glandular tumours developed at the site of introduction.…”