“…These tumors developed at the injection site following repeated injections of a 1.0 percent solution of 2-acetylaminofluorene in arachis oil. Subsequent papers described epithelial and multiple primary tumors which were induced in various organs of the chicken following: (a) repeated injections of 2-acetylaminofluorene into the lumen of the crop (Peacock and Peacock, 1954); (b) repeated injections of methylcholanthrene into the wall of the crop (Peacock and Peacock, 1956); and (c) daily oral doses, Sundays excepted, for three months of 2-acetamidofluorene in sesame oil in gelatine capsules (Campbell, 1955). The induction periods recorded were from two and one-half to five years in length.…”