2 4 



INTRODUCTION. 



The nuclear membranes are not formed about the daughter nuclei In 

 Lilium martagon until after the division of the cell, at least in many 

 instances. Soon after the division of the cell, however, the nuclear 

 membranes are laid down. In all plants examined, each appears first 



FIG. 10. Telophase and daughter nucleus of heterotypic mitosis (Lilium martagon). 

 G, daughter spirem formed by union of granddaughter segments end to end ; each daughter spirem is in 



the form of a disk from whose edges kinoplasmic fibers extend out in direction of cell-wall ; system 



of connecting fibers slightly bulged out at middle. 

 H, the cell-plate appears in center of system of connecting fibers. 



I, J, cell-division is completed, but the daughter nuclei are not yet provided with membranes. 

 K, a daughter nucleus at a later stage with nuclear membrane; chromatin spirem continuous, the free 



ends having been made by knife in sectioning. 



as a weft of kinoplasmic fibers, which are undoubtedly derived from 

 the spindle. It is interesting to note that in Lilium and Podophyllum 

 the nuclear membrane appears in the same form in which it disap- 

 peared during the formation of the spindle. The fact that the nuclear 

 membrane arises first as a weft of kinoplasmic fibers is a strong proof 

 that it is of a kinoplasmic nature. 



