1909] GATES—CHROMOSOMES IN OENOTHERA 199 
PLATE XIII 
Figures in plates XIII and XIV from plants having 21 chromosomes; not 
numbered in developmental order. 
Fic. 11.—Heterotypic spindle in side view, showing 20 or 21 chromosomes, 
not forming an equatorial plate, but loosely aggregated in the median region of the 
spindle; cf. fig. 15. ; 
Fic. 12.—Telophase of heteroptypic mitosis, showing both daughter nuclei; 
one, uncut, shows 10 chromosomes. 
Fic. 13.—Telophase, showing 11 chromosomes and a number of very small 
nucleoli; an unusual condition, probably due to the failure of the nucleoli to 
fuse at an earlier stage. 
Fic. 14.—Telophase, showing 12 bivalent chromosomes, lying closely against 
the wall, tipped at various angles to the plane of view, which gives them a variety 
of appearances; an exceptional case, in which one chromosome too many has 
passed to the end of the spindle; 9 at opposite end; 2 nucleoli. 
Fic. 15.—Metaphase of homotypic mitosis in polar view, showing equatorial 
plates of chromosomes, 10 chromosomes on one spindle and 11 on the other; 
ef. fig. rr. 
PLATE XIV ; 
Fic. 16.—Telophase of homotypic mitosis, showing three daughter nuclei; 
one chromosome left behind in the cytoplasm, leaving 10 chromosomes each in 
two of the daughter nuclei; many chromosomes show characteristic dumb-bell 
shape. 
Fics. 17, 18.—Very early telophase of the heterotypic mitosis, just after the 
nuclear membrane has been formed around the daughter nuclei; one shows to 
bivalent chromosomes, the other 11. 
Fics. 10, 20.—Telophases, each showing 11 bivalent chromosomes. 
Fic. 21.—Telophase with 9 chromosomes only. 
Fic. 22.—Prophase of the homotypic mitosis, showing 11 bivalent chromo- 
somes, which have th pr in the previous telophas ; nuclearmem- 
brane just broken down, its position still occupied by a weft of fibrillae, against 
which the chromosomes lie; cones of the multipolar spindle forming. eae 
Fic. 23.—Same stage as fig. 22; a less common condition, in which spindle 
formation begins on one side of the nucleus; 10 chromosomes, only a few of 
which show bivalent character. is MEE 
_ Fic. 24.—Metaphase of the homotypic mitosis, showing one spindle in side 
view and the other in polar view; chromosomes not all shown. 
__ Fic. 25.—Equatorial plate of homotypic spindle, showing 10 chromosomes 
in a single plane, few showing their bivalent character. es 
1G. 26.—Early anaphase of homotypic mitosis, after division ine babl 
Somes; one spindle in side view, showing only part of the chromosomes  agamersed 
20 in all); the other spindle in polar view, showing 20 chromosomes (two more 
8 "5 this spindle in the next section); 2 nucleoli in the cytoplasm near 
Spindles, 
