1908] YAMAXOUCHI—APOGAMY IN NEPHRODIUM 317 



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



parallel. 



Fig. 9a.— Xucleus in metaphase from previous figure, under higher magnifi- 

 cation. 



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



shovrn in f.g. p. 



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



magnification. 



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



shov/n in Jig. to. 



Fig. iia.^Telophase of nucleus shown in previous figure, under higher 



magnification. 



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



fig 



-Mitotic figure in telophase, shown in fig 



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



Fig. 13.— Section of cushion region; a nucleus v/ithin superficial cell m 



metaphase. 



figur 



magnification. 



Mitosis 



Fig. 14. 



fig 



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



fig 



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. i7.-.Metaphase; two daughter halves of each chromosome just sepa 



rated. 



Figs. 18a, i86.-Two groups of daughter chromosomes in late metaphase of 

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



Fig. ig.-Telophase; cell plate, vertical to surface of prothallium, laid down 

 to cut superficial cell into two daughter cells. 



Fig. 2o:-Portion of section cut through cushion region; three superticia 



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



cell. 



Fig. 2i.-Surface view of a stage similar to that shown in precedmg figure; 

 the three superficial cells in question represented by drawmg 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. 



