Abstract
A two-stage technique for leucocyte migration inhibition has been developed which demonstrates the sensitization of lymph node lymphocytes to colorectal tumour extract. The studies have confirmed that some lymph nodes draining colorectal carcinomata contain sensitized lymphocytes. However, the degree of lymphocyte sensitization to tumour extract does not seem greater than that seen in lymph nodes of the small bowel mesentery or of the peripheral blood.