THE SIMPLEST LIVING THINGS 



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V-shaped pieces (Fig. 42*:). There is a remarkable fact as 

 to the number of these V-shaped pieces. They are identi- 



FlG. 42. Six successive stages in the division of a "cell," to show the 

 appearance of the V-shaped filaments of colourable matter or chromatin. 

 a, resting-cell, with chromatin dispersed as fine irregular filaments in the 

 nucleus ; b, the chromatin takes the form of a wreath with twelve loops 

 it lies horizontally across the cell ; c t the loops break from one another, 

 and form twelve separate V-shaped pieces ; d, each of the twelve pieces 

 divides along its length into two parallel V-shaped pieces ; e, the divided 

 pieces now separate from one another, so as to form two wreath-like 

 groups of twelve V-shaped pieces at each end of the cell ;f, the wall of the 

 cell forms across between the separated groups of V-shaped pieces, which 

 lose their regular arrangement. Each group becomes enclosed in a cap- 

 sule, and is the nucleus of a new cell. This is the regular process of 

 cell-division, and the mode in which the chromatin of the nucleus is 

 broken up, so as to be equally shared by the two daughter cells. In some 

 species of animals the cells have as many as thirty-six V-shaped chromatin 

 bodies ; in others as few as two. Different plants also show a similar 

 difference in the number of chromatin bodies characteristic of the species. 



cal in number in all the cells of one species or kind of 

 animal or plant, but may be of a different number in 



