CELL-DIVISION. 



37 



These lines of cleavage are not meridional furrows which divide the 

 cell symmetrically, but they intersect each other at varying angles, 

 marking off the surface of the cell by a network of grooves, in which 

 the meshes are of an irregular shape and of unequal dimensions (Fig. 

 14, E). 



FIG. 14. Cell-cleavage in Synchitrittm discipens . 



A, sporangium mother-cell. 



B, Portion of cell showing two nuclei and two surface cleavage- furrows. 



C, multinucleate stage, showing progressive cleavage by furrows from surface. 



D, median section showing cleavage further advanced. 



E, section from surface of cell in early stage of cleavage. 



F, cell after segmentation is completed, showing uninucleate protospores. (After Harper.) 



The cleavage is progressive from the surface inward, the furrows deepening 

 in general in a radial direction. Still they may be curved, and are inclined 

 to each other at very varying angles and frequently form intersections at points 

 near the surface of the cell, thus cutting off superficial blocks of protoplasm of 

 varying shapes and sizes (Fig. 14, C), so that we have a central solid mass or 



