Isolated Brown-Pearce carcinoma cells (BPCC) were injected either into the efferent or afferent lymphatics of the popliteal lymph nodes of rabbit and the spread of cancer by metastasis in both cases was studied. The chief findings are as follows: 1. The mortality rate was almost the same in both cases, but the average survival period was shorter in the cases of injection into the efferent lymphatics than in the cases of injection into the afferent lymphatics. 2. Metastasis of cancer in the abdominal cavity occurred to a greater degree in the former cases than in the latter cases. 3. When carcinoma cells were injected into the efferent lymphatics, a retrograde metastasis of cartinoma was observed in the popliteal lymph nodes on the in ected side in two of four cases. 4. In the popliteal lymph node on the opposite side, no metastasis of cancer occurred, regardless of whether carcinoma cells were injected either into the efferent or afferent lymphatics.