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As the developing egg passes along the magnum, more than 80% of the soluble proteins and ovalbumin are released in the lumen and the RNA per milligram of DNA decreases by 31%. This discharge of the secretory goblet cells occurs only in the part of the magnum directly in contact with the yolk. The formation of egg white proteins during the cycle is in two stages. First there is a short period following the release of albumen when the synthesis of ovalbumin is very rapid at the beginning and then decreases to a minimum 5 h after oviposition. Secondly, from 5 h after oviposition to the next discharge of the glandular cells, the concentration of ovalbumin per cell unit increases with a rate of synthesis (Sov) equal to 0.218(t – 7) + 1.119 (Sov, milligram per milligram of DNA; t, number of hours after oviposition). The qualitative analysis of the ovalbumin shows that it is the fraction of dephosphoovalbumin which is synthesized first. It is quickly transformed into diphospho- and triphosphoovalbumin. By surgical removal (4 h after oviposition) of the post ovulatory follicle (Fr) and the F1 follicle, which are responsible for the preovulatory peak of progesterone, or of F2, F3, and F4 follicles, which are responsible for the preovulatory peaks of estrogen and testosterone, a dramatic inhibition of the rate of egg-white protein synthesis is induced.

The hormonal control of ciliogenesis and transformation of mucous cells was studied in the oviduct (magnum) of ovariectomized quails. Estradiol benzoate induces ciliogenesis with doses varying from 10 t~g/day to 100 txg/day after 6 days of treatment. With 100 txg/day, differentiation of some mucous cells is also induced as well as the formation of transitory "mixed cells" which are in the process of ciliogenesis and contain mucous granules.Associated with progesterone (1 mg/day), estradiol benzoate (10 txg/day) induces the differentiation of mucous cells and ciliated cells. The luminal epithelium of quails injected with this mixture is similar to the luminal epithelium observed in the oviduct of laying quails. With the same dose of progesterone (1 mg/day) and 20 ~g/day of estradiol benzoate for 6 days, ciliogenesis is completely inhibited. All epithelial cells are secretory cells.Transformation of 50% of the mucous cells into ciliated cells is obtained by following the previous estradiol-progesterone treatment with the injection of estradiol benzoate (20 /zg/day) for 3 days. Divisions of mucous cells were also observed. It is also possible to induce ciliogenesis in some mucous cells by withdrawing both hormones for 3 days. In this case, no cell divisions were observed.La ciliogen~se s'effectue spontan6ment dans les cellules ~ mucus de l'6pith61ium du magnum des cailles en ponte (article I), mais ce ph6nom~ne n'int6resse qu'une faible proportion des cellules. Dans le but de d6montrer la transformation de cellule h mucus en cellule cili6e, nous avons cherch6 ~ reproduire et ~ g6n6raliser ces transformations par des traitements hormonaux chez des cailles castr6es.Bien que le magnum des oiseaux soit un organe cible des hormones st6roides particuli~rement 6tu-di6, le contr61e hormonal de la ciliogen~se n'a pas 6t6 jusqu'ici clairement d6montr6. Aussi, avant de provoquer la transformation des cellules h mucus en cellules cili6es, nous avons cherch6 h contr61er, chez des cailles ovariectomis6es, la diff6renciation des cellules ~pith61iales soit en cellules cili6es, soit en cellules h mucus. La dose d'oestrog~ne inject6e 460

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