The fact that complete blockage of the lymphatic system has never been produced experimentally is testimony of the difficulty of causing such a condition. The explanation of this remarkable fact must lie in the capacity for the development of a collateral circulation. A multiple origin of the lymphatics from the veins was shown by Sabin.1She stated: "In the pig the lymphatics bud off from the veins in two places, from the anterior cardinal veins and from the veins of the Wolffian body. There are two sets of paired sacs, the jugular and the iliac; and two unpaired sacs, the retroperitoneal and the cisterna chyli." Later investigations by Clark and Clark2demonstrated that in the early stages of development of the chick there are numerous connections between the earliest lymphatics and the blood vessels. The complete picture concerning these anastomoses has not been determined, nor has it been