Hri.i.. U. S. B. F., 19 1 3. 



Pl.ATK X\'III. 



Fig. 5. — Embryo wiih 3-4 somites, x 50. 



Fig. 6. — Embryo with 12-14 somites, x 50. 



Fig. 7. — Embryo with about 12 somites, side view, x 50; H. heart. 



Fig. 8. — Embryo with pigmentation started, inclosed in ovarian follicle, x 45. 



