176 _ .BOTANICAL GAZETTE [MARCH 
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tologist 2: 30-35. 1903. 
11, JANCZEWSKI, EDUARD v., Vergleichende Untersuchungen iiber die Ent- 
wickelungsgeschichte des Archegoniums. Bot. Zeit. 30: 377-393, 40I- 
417, 440-443. 1872. 
12, SCHIFFNER, V., Hepaticae. Die natiirlichen Pflanzenfamilien. 1893. 
13. BiscHOFF, Lehrbuch der Botanik. 1855. 
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Jahresb. Akad. naturwiss. Vereins in Graz. 1875 
15. Bower, F. O., A theory of the strobilus in archegoniate plants, Annals 
of Botany 7: 343-365. 180 : 
. CHAMBERLAIN, C. J., Mitosis in 1 Pellia. Bot. GAZ. 35: 28-51. pls. 12-4. 
1903. 
” 
an 
EXPLANATION OF PLATES IX AND X. 
be magnifications are as follows: figs. zo and 77, X 600; fig. 20, X 
; figs. 27 and 35, X ca. 2500; fig. 76, X 850; all others, X 1000. In 
Senco fe drawings are reduced one-half. 
1G. 5, Diagram of cross section of dorsal furrow passing through a group 
“ nearly mature antheridia, 
I iagram of cross section through group of archegonia; dotted 
lines indicate the limits of the starch-bearing tissue. 
Fie. 7. Longitudinal section through the apex of a plant. 
Fig. 8, Cross section through apical cell region. 
FiG. 9. Horizontal section just below the apical cells with five rudiments 
of ventral scales. 
Figs, 10-11. Stages in the development of the archegonium before ven- 
tral canal cell is cut off; showing also development of tissue from basal cell. 
Figs. 20-21. Cutting off ventral canal cell. 
Fic. 22. Archegonium nearly ready for fertilization. 
Fig. 23. Fertilization; nuclei in contact, the male nearer to the eye in the 
section; egg with concave apex. 
Fie, 2 eg Fertilization ; starch grains in the plastids large and prominent. 
Seman further advanced; the male nucleus almost com- 
pletely anette n the female nucleus, and the egg swollen out to fill com- 
26. An unfertilized archegonium with egg and ventral canal cell 
degenerating. 
Fie. 27. First division of the sporophyte by a transverse wall. 
Fic, 28. First division of the sporophyte by an oblique wall. . 
F1G. 29. Four-celled embryo in form of quadrant. 
Fic. 30. Four cells of embryo in a row. 
F1G. 31. Older embryo in which quadrant can still be distinguished. 
Fig, 32. Embryo beginning to form amphithecium. 
