160 From Matter to Man. 



The cell itself usually consists of a cell-wall com- 

 posed of cellulose (oxygen, hydrogen, carbon), en- 

 closing protoplasm. Within the cell a dark or light 

 globular material is invariably present, called the 

 nucleus — the germ or breeding-place of another 

 cell. 



When unicellular vegetals like the snow-plant re- 

 produce, or multicellular vegetals increase in size, the 

 structural operations in both instances are effected by 

 cell-multiplication. This is accomplished in various 

 ways secondarily, but all reveal in a striking manner 

 fundamentally the source whence vegetals derive their 

 structural energy. For instance, from observations 

 on the coniferae (Strasburger), the nucleus in a 

 pregnant cell assumes a spindle shape (becomes, in 

 fact, a bar-magnet) and parts into parallel filaments 

 from end to end (commencement of like-central- 

 repulsion). From the thickening of the filaments in 

 the centre, a " nucleus plate " then forms, which anon 

 splits into halves, and (by like-central-repulsion) each 

 half recedes to the poles of the spindle. Here they 

 constitute two nuclei, and soon after the whole proto- 

 plasm of the cell divides, each half surrounds the 

 two new nuclei, a cellulose wall encloses them, and 

 through this virtual parental suicide two daughter- 

 cells are born. Fundamental magnetic action could 

 not be better illustrated with a bar-magnet and iron 

 filings than by those microscopic cells acting auto- 

 matically, thus furnishing an apt illustration of the 

 truth of our theory and of the continuity which 



