Abstract
It has been demonstrated that Hymenolepis microstoma in mice treated with cortisone grow larger than those in control mice.The possibility of this being an immunosuppressive or growth-stimulating effect is discussed since the results from two strains of mice are different.Antibody production is suppressed in the cortisone-treated animals and it is suggested that the circulating antibody normally affects a partial rejection of the worm.I am grateful to Professor C. A. Hopkins and Dr T. S. C. Orr for many helpful comments during the course of this work and especially to Professor C. A. Hopkins for the facilities which he has placed at my disposal. Many thanks also to Miss Gillian Moore and Mr Jack Keys for their expert technical assistance. This work was in part supported by a grant from Fisons Pharmaceuticals Ltd.