3 i8 BOTANICAL GAZETTE [may 



Fig. 23. — Prophase; chromosomes irregularly crowded in a mass. 



Fig. 24.— Late prophase, showing chromosomes before their arrangement in 

 an equatorial plate. 



Fig. 25. — Polar view of metaphase, where L-shaped chromosomes are ar- 

 ranged in an equatorial plate; vertical arms of L's are visible as dots and lateral 

 arms as radiating lines. 



Fig. 26. — Late metaphase; two daughter halves of each chromosome have 

 just separated. 



Fig. 27. — Early telophase, showing polar view of a group of daughter chro- 

 mosomes; 66 chromosomes present. 



Fig. 28. — Section of cushion region where a sporophytic structure has been 

 worked out. 



Fig. 28a. — Approximate portion that belongs to the sporophytic structure 

 shown in the preceding figure, under higher magnification; difference of size of 

 cells in prothallial region and sporophytic structure shown. 



Fig. 29. — Section through sporophyte apogamously produced, in a consider- 

 ably later stage; one of the two apical cells seen is a leaf initial, the other a root 

 initial; apical cell of stem not drawn in this section; no structure standing for 

 a foot is present. 



