“…A discussion on the development and significance of these lamellar bodies is beyond the aim of the present paper. They are, anyway, peculiar to granular pneumocytes (or type B or type II alveolar cells) and their presence in neoplastic cells has been regarded as ultrastructural evidence of the alveolar origin of both human and animal lung tumours (Klarner and Gieseking, 1960;Nagaishi et al, 1965;Hattori et al, 1967;Brooks, 1968;Adamson et al, 1969;Flaks and Flaks, 1969;Johnston et al, 1971;Nisbet et al, 1971;Nash et al, 1972 Adamson et al (1969), Coalson et al (1970, and Nash et al (1972), but not by Geller and Toker (1969), and Razzuk et al (1970).…”