“…in the oesophagus (Andrew, 1957;Mei, 1965Mei, , 1970bClarke & Davison, 1975), the stomach (Paintal, 1954;Iggo, 1955Iggo, , 1957aLeek, 1969; Mei, 1970b;Harding & Leek, 1972a;Andrews, Grundy & Scratcherd, 1980;in particular), the small intestine (Paintal, 1957;Iggo, 1957 b;Davison, 1972; Mei, 1970b;Ranieri, Mei & Crousillat, 1973;Morrison, 1973;Floyd, Hick & Morrison, 1976;Clarke & Davison, 1978) and the colon (Mei, 1970a, b;Clifton, Coggeshall, Vance & Willis, 1976). Some of these receptors are located in the muscular layers and are sensitive to normal distensions or contractions affecting the viscera.…”