1908] BURLINGAME—PODOCARPUS 177 
Fic. 5.—Detail of sporangium of same age as preceding, showing relations 
of wall, tapetum (#), and sporogenous tissue (sp). 
Fic. 6.—Cross-section through sporangia; vb, vascular bundle. 
Fic. 7.—Cell of the sporogenous tissue about one division short of the 
mother cell stage. 
Fic. 6.—Detail of a nucleus a little later than preceding, showing the nuclear 
materials beginning to arrange themselves into threads with here and there deeply 
staining chromatin knots. : 
Fic. 9.—Surface view of a still older nucleus showing the strands more dis- 
tinct and larger. 
Fic. 10.—The definitely organized spirem with unusually distinct chromatic 
knots; the spirem is usually more homogeneous and stains more evenly. 
Fic. 11,—A very thin section of a nucleus whose spirem is beginning to seg- 
ment into chromosomes; compared with fig. 7, it shows the variation in size and 
shape of the sporogenous cells. 
Fic. toe section of a cell in telophase showing about half of 
each group of chromosomes; the spindle is curved with the concavity toward the 
observer, 
Fic. 13.—Showing the reconstruction of the daughter nuclei. 
1G, 14.—Mother cell showing the emergence of the chromosomes from the ~ 
gtanular mass out of which the spindle arises; the granular materials are actually 
much denser than shown in this figure and nearly conceal the chromosomes. 
1G. 15.—Longitudinal section of the heterotypic spindle. 
Fic. 16.—Late anaphase of the heterotypic mitosis. 
Fic. 17.—The homotypic mitosis, 
PLATE IX oe 
(Figs. 18-27, 3 3 are P. totarra Hallii; figs. 28-32 are P. ner? 
Fic. 18.—Section of microspore slightly oblique to the wings; 7, intine; @, 
exine. 
Fic. 19.—Male gametophyte showing first prothallial cell (p:) divided, no 
Second prothallial (p,) cell, primary spermatogenous cell (ps), and in next section 
the tube nucleus (). primary 
FIG. 20.—Same stage as preceding except that there are here two 
Prothallial cells (p,), the second of which has divided (only one, 2, of the seg- 
ments shown). : 
Fic. 21.—Same as fig. 19 except that the single primary prothallial cell (p:) 
has not divided; #, tube nucleus. a d 
Fic. 22.—Male gametophyte showing first prothallial (p;) undivided, secon 
(?). divided once, primary spermatogenous cell (ps), and tube nucleus (2). oe 
_ Fic. 23.—Same as preceding except that first prothallial cell (p) has x 
derivatives of the second prothallial cell (p,); adjacent sections show that there 
are here four derivatives of the second prothallial cell. , 
