Hypopituitary dwarf Snell—Bagg mice have previously been shown to have a reduced capacity to produce antibody to sheep red cells and to reject foreign skin grafts. Their thymuses, spleens and lymph nodes are hypoplastic. However, quantitative estimation of their serum immunoglobulin levels reveals no significant difference from the values seen in normal litter-mates. Immunoelectrophoretic analysis shows no overall differences in immunoglobulin pattern between normal and dwarf mouse serum except a possible alteration in distribution of the IgG subtypes
