Johnson. — Nuclear Division. 



PLATE II. 



Fig. 14. Piece of the serosa from an advanced embryo, with four adjacent tri- 

 nucleate cells (1, 2, 3, 4) ; nuclei of cell a and the large cell farthest 

 to left have undergone degeneration. X 90. 



Fig. 15. Three cells of the serosa from an old embryo to show recession of daugh- 

 ter nuclei towards the ends of the cells. X 90. 



Figs. 1&-20 are from the amnion. 



Figs. 16-19. Stages in the division of amniotic nuclei. In Figure 18 three stages 

 are shown, a, b, c. X 800. 



Fig. 20. Two amniotic cells, apparentl}' formed by recent division. X 375. 



Figs. 21-26 are from the capsular epithelium. 



Figs. 21-23. Cells showing successive stages of nuclear division. X 800. 



Figs. 24-26. Cells to show the degeneration of nuclei. In Figure 24 the nuclei 

 a.e but slightly differentiated; in Figure 25 the pale nucleus has 

 become much larger and very faint , in Figure 26 it has disappeared 

 altogether. X 800. 



