This paper gives evidence that as the cotton bolls grow older they are less suceptible to boll weevil, Anthonomus grandis , injury, and the immunity at given ages varies with the variety. Dixie Triumph, Webber 49 and Humco Cleveland were the varieties studied, the first mentioned is the most susceptible and the last the most resistant. There is no correlation between the number of feeding punctures or the number of egg punctures and the percentage of cotton loss. Neither is there any relation between the thickness of hull and susceptibility to weevil damage, in spite of the fact that the weevils lay fewer eggs in the thick-hulled varieties. The determining factor is the hardness of bolls because varieties with the hardest bolls, as determined by the number of grams pressure required to puncture them, show also the least per cent of cotton loss.