Chymotrypsin inhibitors in haemolymph and eggs of the silkworm, bombyx mori: developmental changes in inhibitory activity

1. 1. The activity of chymotrypsin inhibitor was assayed at larval and pupal stages. 2. 2. The value was the highest at the later half of the 5th instar, although some differences in pattern of developmental changes were seen between the sexes. 3. 3. The electrophoretic pattern in activity of the chymotrypsin inhibitors exhibited little variation according to the sex and developmental stage. 4. 4. Eggs were found to possess the chymotrypsin inhibitors. 5. 5. The transplantation of ovary as well as a mating experiment showed that the inhibitors in the eggs at early stages were of the maternal origin, and that zygote-dependent synthesis of chymotrypsin inhibitors occurred after day 5 of embryogenesis.