Abstract
1. The blood supply to the lower colon has been investigated in the rabbits. and compared with the arterial arrangements in man.
2. Ligation experiments of 6 types have been undertaken in 45 animals, and the morphology of the collateral circulation and its evolution have been studied in the rabbits sacrificed at various intervals from 1 to 4 weeks after operation.
3. The vascular reserve of the lower colon is very great. The only effect in usually a temporary ischemia in the area of the interrupted circulation due to the ligation. Necrotic changes of the lower colon were only occurred when the inferior mesenteric artery is occulded and in addition many sigmoid arteries are occulded.
4. The intrinsic anastomosis of vessels in the wall of the colon are inadequate to compensate fully for interruption of sigmoid artery.
