Abstract
1. The white-blue fluorescent substance in the extracts of wings of the Papilionid butterflies reported in the previous paper by the authors, was proved to be identical with kynurenine both by comparison with synthetic kynurenine and by biological test.
2. Using the markings on the wings of P. helenus and P. protenor, the substance (kynurenine) was proved to be stored up only in the whiteyellow scales and not in the black scales.
3. Kynurenine in the wings of P. machaon. P. xuthus, P. helenus, and P. pro tenor was colorimetrically determined separately with regard to sex. In P. machaon and P. xuthus, the quantity of kynurenine was proved to be larger in the males than in the females. In P. helenus, sex difference was not recognized. In P. protenor, only the males were examined. In the latter two species, furthermore, quantity of kynurenine per cm.2 of the markings was also estimated.
4. The relation of kynurenine to the pigments of the wings and the markings, and the possible systematization of the Papilionid butter-flies according to kynurenine content were discussed.
The authors wish to express their gratitude to Professor Katashi Makinoof the Tokyo Jikeikai School of Medicine for a generous gift of synthetic kynurenine, and to Professor H. Kawa shim a and Professor M. Kumano for their encouragement.
