Castle. — Ciona intestinalis. 



PLATE n. 



Figs. 7-10. Four sections through an impregnated egg; magnification, 560 diam- 



Fig. 7. Fo'urth"sectionof series, showing the male pronucleus and archoplasmic 



spheres. Compare Figs. 11 and 12. 

 Fig 8 Seventh section of series, showing the female pronucleus. 

 Fig 9 Tenth section of series, showing the fen.ale archoplasm. 

 Fiff 10 Twelfth section of series, showing polar globules. 

 Fig. 11. Graphic reconstruction of the series on a plane, perpendicular to that of 



Fig. 7, indicated by the line a h. Fig. 7. , ■ r ^t 



Fig. 12. A similar reconstruction on a perpendicular plane, the projection of 



which is the line a' 6', Fig. 7. 



