[Vitelline morphogenesis in a teratocarcinoma of mice]

Morphogenesis like cyto-differentiation is expressed in Mouse teratocarcinomas. The presence in certain tumours, of yolk-sac cavities combining trophoblast, Reichert's membranes and parietal distal endoderm in spite of the absence of included embryoïd structures, suggests that there is a precursor cell common to there extra-embryonic components.