This experiment was attempted to investigate the effect of removal of suboesophageal ganglion of Bombyx mori on the changes of free amino acids and fluorescent substances by means of paper chromatography. 1. There are no differences of quantity and component of free amino acids of formed eggs in moths between treatment and control. 2. Riboflavine content of formed eggs in treated moths is less than that of formed eggs in untreated moths. 3. Fluorescent substance which appeared on Rf value 0.06 was not detected in formed eggs of treated moths but found in those of control. 4. Fluorescent substance which appeared on Rf value 0 was noted in formed eggs of treated moths but not in those of control.