“…Histological examina tion of the cartilage and bone that was formed in grafted hearts, together with observations made upon dissected hearts, strongly suggest that these tissues developed from the connective tissue immediately beneath the endocardium. Specifically what conditions triggered such growths is not known, but the literature contains reports of similar cases arising in association with necrotic heart muscle in man [C ohen and L evine, 1937;Brown and E vans, 1940;E delstein, 1946;F inestone and F eschickter, 1949], chickens [Lehocsky-M ona and M cCandless, 1964] and rats [Farris et ai, 1946;Selye et al, 1967;Somogyi and K ovacs, 1969].…”