OLIGOENTOMATA AND APTILOTA 



167 



Fig. 67. — Isotoma. Blastoderm stage, (bid) Blastodenn. {gc) Germ cells, (yc) Yolk 



cells. 



"^"^^^M^M^ 



Fig. 68. — Isotoma. Two-layered stage, (gc) Gorm cells, (il) Inner layer, (yc) Yolk 



cells. 



dc 



'^^M^^mk^^S^^ji 



Fig. 69. — Isotoma. Anlage of dorsal organ (dc). (ect) Ectoderm. 



