The present study was undertaken in an effort to clarify the portion where the pigment of the egg-covering are formed in the Japanese quail oviduct. Results obtained and conclusion reached may be summarized as follows:
1. The mucous membrane of the uterus in laying state colors in dark brown and fluoresces strongly red color. In addition, also the uterine liquid fluoresces red color. Microscopically, the coloration and the fluorescence of the uterus are represented by the yellow or brown pigment granules in the apical cells of the mucous epithelium.
2. The colored figures in the surface of the egg are represented by the pigment embedded in the cuticule, cuticular pigment. This pigment is granular, brown and fluorescent in red. In the present study, this pigment was dealt. The shell surface of the egg are white or faint greenish or bluish, and non-fluorescent.
3. The pigment of the cuticule and the uterine epithelium show such similarities as yellow or brown color, granular nature, solubility in metalic acid solutions, primary and secondary fluorescence in red color, and these characters are peculiar to porphyrin.
4. Absorption maxima of the pigments in the uterus and in the cuticule were measured in methylester-form and SORET band is presented in each spectrum, so that these two pigments are porphyrins. Moreover, these spectra contain some of the absorption maxima corresponded with those of ooporphyrin described by FISCHER & KÖGL.
5. The utrine pigment is fixed well in REGAuo's solution and ZENKER-formol and disappeared in CARNOY's or BOUIN's solution.
6. The uterine pigment changes in the volume of the granules in the apical cells related to the egg-formation cycle; that is, in the uterus containing a calcified white egg the granules are accumulated in the cells and in the uterus containing a colored egg, the granules are little in each of these cells, and in post-layed state, the volume of the granules are variable. Accordingly, this pigment granule may be considered as secreted in the cells and released to cuticular pigment in the uterine lumen.
7. In the apical cells, also, the PAS positive granules are observable. These granules present feautres in their volumes showing parallel to the pigment granules. Therefore, the granules, too, may be taked as secred and released with the pigment granule, and thought to be related with the cuticular formation.