Ch. VI, 4] NATURE OF FERTILIZATION 



281 



egg nucleus, as shown diagrammatically in Fig. 194. It is 

 true, the chromatin is in the resting state at this time, so 

 that the chromosomes cannot be distinguished ; but at the 



T-.A 



Fig. 193. — Stages in typical cell division in gromng tissue, somewhat 

 generalized. 



1, Resting cell. 2-5, The chromatin collecting into chromosomes, which 

 become definite in number and outline. 6, Splitting of each chromosome 

 length'U'ise into two. 7, 8, The chromosomes growing shorter and thicker. 

 9, 10, They collect in the equatorial plate of the forming spindle. 11, 12, 

 13, Separation of the pairs of chromosomes. 14, 15, 16, Formation of the new 

 nuclei, return of the chromosomes to the chromatin threads, and formation 

 of a new wall. Thus are produced two new cells from division of the original 

 one. Next these daughter cells grow to the full size of the parent cell, 

 after which they again divide in the same manner. (After Strasburger.) 



