574 MAYOR. 



Figures 18-20, 25. Individuals containing two sporoblasts. 



Figure 18. The left sporoblast. At opposite ends are seen the two 

 valve-cells containing their flattened nuclei. The germ-nuclei 

 are the two more deeply-staining ones nearest the left side 

 of the sporoblast. The two nuclei nearest the right side are 

 the nuclei of the capsulogenous cells. 



Figure 19. Diagram showing the position of the left and right sporo- 

 blasts and their nuclei in the myxosporidium. 



Figures 20, 25. The right sporoblast; Figure 20 showing the appearance 

 at a high focus, at which the valve-cells and the nuclei of the 

 capsulogenous cells are seen; Figure 25 showing the appear- 

 ance at a low focus, at which the germ-nuclei become visible. 



Figures 21, 22. Two views of an isolated sporoblast; Figure 21 at a high 

 focus, showing near the ends the two nuclei of the capsulogen- 

 ous cells and at the left the two more deeply-staining germ- 

 nuclei; Figure 22, at a deeper focus, showing the two nuclei 

 of the cells which form the valves of the shell. 



Figures 23, 24. Two views of an isolated sporoblast; Figure 23 at a high 

 focus, showing at the ends the two cells which form the valves 

 of the shell and near the center the two germ-nuclei; Figure 

 24 at a lower focus, showing the two capsulogenous cells. 



