THE WALLFLOWER 



of plants such as the Wallflower, and indeed in all 

 plants except the lowest. Wherever new organs are 

 in course of development we find cell-division going 

 on, as, for example, at all growing-points whether of 

 stem or root. We will suppose, as is generally the 

 case, that the cell which is about to divide has a single 

 nucleus to start with. The first obvious changes which 

 take place are in the nucleus. The changes gone through 



A B 



FIG. 17. Dividing cells from the young seed of Fritillaria. 

 A, The two daughter-nuclei have been formed, but the 

 new cell-wall between them does not yet reach across 

 the cell. B, Later stage ; the new cell-wall now com- 

 pletely divides the mother-cell into two parts. (After 

 Strasburger.) Magnified 240 times. 



are of a very complicated character, but their ultimate 

 effect is that the nucleus becomes divided into two 

 exactly equal and similar parts, the daughter-nuclei. 

 So precise is the accuracy of the division, that every 

 single minute fibril of which the framework of the 

 parent nucleus consists is split lengthways into two 

 identical halves, one of which goes to each of the 

 daughter -nuclei The latter remain for a time con- 

 nected by delicate threads of protoplasm. 1 The new 

 cell-wall is formed at right angles to these threads 



1 The details of nuclear division, a subject of the highest possible 

 importance, must be studied in more advanced text-books. 



