Artificially induced metastasis by cells from spontaneous Lucké renal adenocarcinoma. 
This communication reports the development of tumour colonies in various organs after vascular dissemination of disaggregated cells from spontaneously arising Lucké renal adenocarcinomata in Cyclosporin-A-treated allogeneic frogs, Rana pipiens.  The sites of tumour cell colonies were mesonephros, lung, bladder, mesentery, fat body and muscle.  It was also found that digestion of these tumours with collagenase is an effective means of obtaining sufficient dissociated viable cells for large experiments and that cryo-preservation does not abrogate the ability of these cells to form metastatic deposits.  This report, therefore, introduces a new tumour system for the study of factors affecting metastasis using naturally occurring tumours.