152 0. M. CHILD. 



Plate IX. 



Fig. 4. Cross-section of the vas deferens at a somewhat later stage. 



Fig. 5. Longitudinal section of a vas efferens. 



Fig. 6. A portion of the wall of the developing oviduct, showing one case of 

 mitosis. 



FlG. 7. Probably a developing nephridial duct in cross-section. 



FlG. 8. From the region of the lateral longitudinal nerve-cords in the "neck." 



