Castle. — Ciona intestinalis. 



PLATE VIII. 



Six successive views (obliquely from the left, above, and behind) of a living egg; 

 magnification, 315 diameters. Arrows indicate the direction of spindles. 



Fig. 45. 2-cell stage, x, region of finely granular protoplasm (cf. description of 



Plate III. Fig. 17). 

 Fig. 46. 4-cell stage, just formed. 

 Fig. 47. 8-cell stage, approaching. 



Fig. 48. 8-celI stage, fully formed (viewed as a transparent object). 

 Fig. 49. 16-cell stage. 

 Fig. 50. 24-cell stage. During the formation of the 24-cell stage, the egg has 



rotated so that the view is almost exactly dorsal. 



