抄録
1) The current experiment was performed to clarify the progression of fibroin in the inside of the silkgland during growth of the fifth instar, by tracing radioactive fibroin which was made of C14 glycine.
2) The radioactive glycine, 0.5μc per larva, was given per os to silkworms, Si 122XNichi 122, in different periods from the beginning of the fifth instar to the end of the fifth instar. These worms were reared on mulberry leaves until they became matured larvae, one day before spinning. At intervals of 24 hours after the radioactive meal, the silkgland isolated from silkworm was used for making a radioautograph of the longitudinal section of the middle division.
3) Each fibroin synthesized by the posterior division at different period of the fifth instar moves in an ordered fashion as shown in Fig. 1, in the inside of the gland along the middle and the anterior division during growth of the silkworm.
4) Fibroin present in the middle division at the end of the fifth stage is due to the successive disposition, in the order synthesized, of each portion of fibroin synthesized at different periods of the fifth stage.
