This report concerns the augmentation of peritoneal dialysis using alternating hyper/hypoosmotic peritoneal dialysates, and covers a detailed examination of the longest lived, anephric goat to be maintained using this delivery system. Experimental results show that with this technique: 1) urea clearance can be increased some 200% over control values, 2) the convective transport of urea is unimportant and the increased urea clearance is due primarily to increased peritoneal permeability, 3) net ultrafiltration and electrolyte balance can be easily controlled by variation of total electrolyte and glucose about an appropriate mean. A detailed autopsy failed to demonstrate any gross or microscopic pathology.