Drosophila embryo stage embryonic stage 10 Stage 10 begins with the appearance of the stomodeal invagination, slightly ventral to the anterior pole. Periodic furrows appear in the embryonic epidermis around the middle of the stage. The germ band continues to extend, reaching its maximum extent of 75% egg length towards the end of the stage. The end of the stage is marked by the beginning of invagination of the tracheal placodes. Duration at 25 degrees : approximately 60 minutes (260-320 minutes after egg laying). Temporal ordering number - 290. Catherine Leroy FBdv:00005324