178 BOTANICAL GAZETTE [SEPTEMBER 
Fic. 12.—Upper half of median longitudinal section of nucellus after wall 
formation is complete in the prothallus, showing the characteristic position of the 
pollen tube; August 25, 1908. X24 
Fic. 13.—Tip of pollen tube > ie 12. X3I10. 
Fic. 14.—Body cell nucleus of fig. 13. 1240. 
1G. 15.—Upper half of median longitudinal section of nucellus, 1”, and 
prothallus, p, showing position of pollen tube and of archegonia; drawn from sev- 
eral . t, pollen tube; January 7, 1909. X28. 
Fic. 16.—The lowest group of archegonia of jig. 15, two containing pro 
sunbigee Xt 
G. 17.—Suspensor bearing a single embryo cell at its apex; note multi- 
nucleate prothallus cells in this and previous figure; s, suspensor; ¢, embryo cell; 
January 7, 1909. X310. 
1G, 18.—Very young embryo in median longitudinal section; March 8, 1968 
Fic. 19.—Older embryo, showing dermatogen differentiated and embryonal 
tubes; January 7, 1 
Fic. 20.—Outline sketch of median longitudinal section of nearly mature 
embryo; March 8, 1908. Xg. 
Fic. 21.—Two multinucleate cells from an old prothallus; March 8, 1908: 
X54. 
Fic, 22.—Dividing nucleus from an embryo between the ages of those shown 
in figs. 17 and 18 respectively. X 1500. 
