12 rat liver tumors (high, purely and low differentiated hepatomas and adenocarcinomas), 3 kidney tumors, 1 lymphosarcoma and 1 round cell sarcoma of the uterus were transplanted and passed trough anterior chamber of the allogenic rat eyes. In 8 primary transplants of the liver tumors differentiation traits increased; three of them were morphologically undistinguishable from the normal liver tissue. In some transplants of embryonic liver and kidney displasia was detected. The results obtained give evidence in favor of a very high cytological variability of tumors at the early steps of progression, and indicate that the cultivation in the anterior chamber of the eye may be a proper model for investigation of cytological variability of both malignant and normal tissues.