カワムツの孵化腺の発生

1. Jn embryos shortly before hatching, the gland cells, in number 200 - 300, distribute on the body surface at the fore part of the head except the top, and the frontal part of the yolk sac. The granules contained in the gland cells are strongly stained with picro-blue-black.
2. The glands are derived from the epidermal cells on the anterior, lower part of the head, and disperse on the part as mentioned above.
3. After having finished the discharge of the secretory substances the glands degenerate rapidly within about 2 days.
In closing this paper, the writer wishes to express his cordial thanks to Ass. Prof. M. Ouji for many helpful suggestions.