1918] OTTLEY—IMPATIENS 315 
PLATE XIV 
Fig. 1.—Vertical section of ovule before integuments have appeared; 
X828. 
Fic. 2.—Vertical section of sh showing origin of inner integument and 
large megaspore mother cell; 8x 
Fic. 3.—Vertical section of vale slightly older than fig. 2; 810. 
Fic. 4.—Vertical section of ovule with nucleus of megaspore mother cell 
in synapsis; X8ro. 
Fic. 5.—Vertical section of megaspore mother cell with nucleus in second 
contraction stage of prophase of heterotypic division; X 1620. 
Fic. 6.—Vertical section of ovule showing origin of outer integument and 
devescnted spirem of megaspore mother cell; X 500. 
Fic. 7.—Vertical section of megaspore mother cell showing tetrad forma- 
tion in nucleus; X 1300. 
Fic. 8.—Vertical section of nucellus after 2-celled axial row has been 
formed; 1300. 
Fic. 9.—Vertical section of portion of ovule containing 2-nucleate embryo 
sac; 1000 
Fic. to. mae ertical section of 2-nucleate embryo sac with surrounding 
nucellus and tapetum; nuclei of embryo sac in prophase of division; 810. 
Fic. 11.—Vertical ain of young 4-nucleate embryo sac; combination 
of 3 serial sections; 
Fic. 12.—Vertical pe of slightly older sac with nucellus and re 
integrating epidermis; 810 
Fic. 13.—Vertical ection of still older 4-nucleate embryo sac with basal 
ion of epidermis still intact; 1000. 
G. 14.—Vertical section of early 8-nucleate embryo sac with nucellus at 
base tis instep at either side; 
G. 15.—Vertical section of early sage in formation of egg apparatus: 
synergid siche each above a large vacuole; X 1000. 
Fic. 16.—Vertical section of micropylar region of embryo sac showing 
2 synergids; synergid nuclei have reached center of the 2 synergid cells; 
X 1000. 
Fic. 17.—Vertical section of 8-nucleate embryo sac before the 2 polar 
nected have reached their position directly beneath egg; combination of 2 serial 
sections; X 1000 
Fic. 1 #i--Veitical section of antipodal region of 8-nucleate sac before 
antipodal polar has moved toward micropylar polar; the 3 antipodals show as 
rial cells; combination of 2 serial sections; 1620. 
. 19.—Vertical section of embryo sac after antipodals have disappeared 
and aes haustorium has begun to develop; micropylar tip of sac was 
covered by inner integument; X 1000. 
1G. 20.—Cross-section of microsporangium while spore mother cells are 
in synaptic stage; 500. 
