highly significantP < 0 001
There was no difference between the survival rates of the 3 groups when given more than 5 x 104 tumour cells, as all the animals died. There was a slight increase in the survival 90 80- 70- iso , 50 *s *\A 40 - 3 0 rate of the splenectomized group given 104 cells: 23.8% compared with 6.7% for normal and 10% for sham-operated mice (P < 0.01). There was a marked improvement in the survival rate of splenectomized mice that received 103 tumour cells, 81.6% compared with 11.5% and 20% for normal and sham-operated animals respectively. This is highly significant, with P < 0 001 calculated by the x2 test.