1909] OTTLEY—JUNIPERUS 45 
Fic. 7.—Early stage in the piercing of the nucellar cap by the pollen tube of 
J. communis; June 3, 1905. 884. 
Fic. 8.—Young pollen tube of J. virginiana; June 1, 1905. X 382. 
Fic. 9.—Upper part of the pollen tube of J. communis, ae the stalk cell 
and the generative cell; May 8, 1905. 1850. 
Fic. 1o.—Pollen tube of J. communis, showing the tearing-away of the cyto- 
plasm of the stalk cell from the wall of the old pollen grain; May 10, 1905. 884. 
Fic. 11.—Portion of pollen tube of J. virginiana, midway through the nucel- 
lus, showing the generative cell with the tube and the stalk nuclei just beneath 
it. X 1850 
PLATE II 
Fic. 12.—Lower portion of an older pollen tube of J. virginiana, showing 
the two free nuclei below the generative cell. 1850. 
Fic. 13.—The generative cell of J. communis, just before division; June 9, 
1903. X 884 
Fic. 14.—Longitudinal section of ovule of J. communis, showing nucellus 
and integument; spongy tissue not yet clearly differentiated; May 19, 1905. 116. 
Fic. 15.—Longitudinal section of ovule of J. virginiana, showing an occa- 
sional method of closing the micropyle. 116. 
Fic. 16.—Longitudinal section of ovule of J. communis in winter condition, 
me usual method of closing of micropyle; March 28, 1905. X 116. 
G. 17.—Macrospore mother cell of J. communis; April 14, 1905. 704. 
io. 18.—Macrospore mother cell of J. communis, in prophase of division 
with spongy tissue around it; April 17, 1905. 70 
Fics. 19-21.—Different stages in the division of the macrospore mother cell 
of J. communis; April 17, 1905. 1850. 
Fic. 22.—Two-celled embryo sac of J. communis; May I, 1905. 704. 
PLATE III 
IG. 23.—Longitudinal section of the nucellus of J. communis, sho wing the 
hollow prothallium almost a year after pollination; May 5, 1905. 
G. 24.—Prothallium of J. communis, almost closed at the center, with arche- 
gonia at the micropylar end; May 30, X 62. 
Fic. 25.—Stages in the ieninee cit of archegonia in the same archegonial 
complex of J. communis; May 30, 1903. 704. 
Fic. 26.—Longitudinal section of archegonium of J. communis, at the time 
of the division of the central cell; nucleus in prophase of division; large central 
vacuole and prominent radiations; June 20, 1905. X 704. 
Fic. 27.—Longitudinal section of an archegonial complex of J. communis, 
with the tip of the pollen tube above it; June 20, 1905. 382. 
PLATE 1V 
Fic. 28.—Upper portion of archegonium of J. communis just before fertiliza- 
tion; June 20, 1905. X 1016. 
Fics. 29, 30.—Conjugation of sexual nuclei of J. communis, showing sheath 
of denser cytoplasm; June 20, 1905. X 1850, 884. 
