Having compared world oncological literatures with his own series [about 1000 cases] of tumours of the stomach, small intestine, appendix, and large intestine [diagnosed bioptically as well as necroptically], the author recommends a simplification of the usual classification scheme on the grounds that mesenchymal and neuroectodermal tumours do not require any other scheme than for soft tissue tumours. Likewise, anal tumours so long as there are skin variants do not call for any independent classification. The author recommends the following classification of epithelial tumours: Adenoma: a] tubular; b] villous; c] other types. Adenomatoid processes: a] harmartoma polyp; b] heterotopia [gastric, intestinal, duodenal, endometriosis, others]; c] hyperplasia; d] precanceroses e] others. Carcinoma: a] tubular; b] diffuse; c] solid; d] others [in situ, intramucous, tubopapillary, gelatinous, adenosquamous, cloacogenic, in ulcere peptico, non-classifiable]. The other tumours are mostly difficult to distinguish from metastases, and should therefore be assessed individually.