1908] YAMANOUCHI—APOGAMY IN NEPHRODIUM 317 



Fig. 9. — Section through region where later a cushion arises; narrow cells 

 parallel. 



Fig. ga. — Nucleus in metaphase from previous figure, under higher magnifi- 

 cation. 



Fig. 10. — Section through region forming cushion; next stage after that 

 shown in fig. p. 



Fig. 10a. — Nucleus in late prophase from previous figure, under higher 

 magnification. 



Fig. 11.— Section through region forming cushion; later stage than that 

 shown in fig. 10. 



Fig. 11a. — Telophase of nucleus shown in previous figure, under higher 

 magnification. 



Fig. 12. — Section including cushion region; next stage after that given in 

 fig. 11. 



Fig. 12a. — Mitotic figure in telophase, shown in fig. 12, under higher magni- 

 fication; cell plate laid down parallel to surface of prothallium. 



Fig. 13.— Section of cushion region; a nucleus within superficial cell in 

 metaphase. 



Fig. 13a.— Nucleus in metaphase, shown in the previous figure, under higher 

 magnification. 



Mitosis in conspicuous superficial cell 



Fig. 14. — One of the sections of the cushion region shown in fig. j (text) ; 

 one superficial cell has increased considerably in size; nucleus in prophase. 



Fig. 14a.— Nucleus in prophase, shown in fig. 14, under higher magnifica- 

 tion; several ends of the spirem seen are cut sections; two nucleoli present. 



Fig. 15. — Late prophase, showing long slender chromosomes before arrange- 

 ment in an equatorial plate. 



PLA TE X 



Fig. 16. — Polar view of the late prophase shown in preceding figure. 



Fig. 17.— Metaphase; two daughter halves of each chromosome just sepa- 

 rated. 



Figs. 18a, 18&— Two groups of daughter chromosomes in late metaphase of 

 a nucleus cut obliquely into two sections; 66 chromosomes present. 



Fig. 19.— Telophase; cell plate, vertical to surface of prothallium, laid down 

 to cut superficial cell into two daughter cells. 



Fig. 20.— Portion of section cut through cushion region; three superficial 

 cells drawn showing contents, middle one of which is cut obliquely as an apical 

 cell. 



Fig. 21.— Surface view of a stage similar to that shown in preceding figure; 

 the three superficial cells in question represented by drawing all the contents. 

 Mitosis in interior cells directly beneath superficial cells 



Fig. 22.— Nucleus containing a spirem; visible ends of spirem are cut sec- 

 tions. 



