Abstract
Regarding the amylase activity of Bomhyx mori, there are four genetical strains, +ae, +be, ae and be. Comparative studies of the amylase action of these strains were carried out by means of the sugar-measurement and the iodine-starch reaction. The results show that the “amylase free strains”, ae and be, are not completely free from amylase but they show the enzymic activity, though very weak, in the later larval stage and also in the pupal stage. According to Matsumura and Kikkawa, there are various grades of amylase activity in +ae and +be. From these facts, it may be supposed that the amylase activity in digestive and body fluid would cover a wide range of degree from + to -. Furthermore, as reported by Matsumura et al., amylase activity in the silkworm is influenced by various factors, such as rearing conditions and the developmental stages. The genetical phenomena of the amylase action in the silkworm seem to be very complicated.
