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Dec, 1921] TAYLOR — CYRTANTHUS PARVIFLORUS BAKER 5O3 
the polar nuclei have united during the maturation of the embryo sac and 
have passed to the antipodal end where the triple fusion occurs. Both 
zygote and primary endosperm nuclei then remain in a state of rest with 
finely divided extra-nucleolar chromatin for some time. Three or four 
successive divisions of the endosperm nucleus precede the first division of 
the zygote, which occurs in from 94 to 118 hours after pollination. The 
first and second endosperm mitoses occur close to the antipodals at the 
base of the embryo sac, but the nuclei produced soon move down along the 
sides of the sac and with subsequent free nuclear divisions become equally 
distributed in the peripheral cytoplasm. The sac is large and increases in 
size rapidly after fiertilization, so that there seems to be no evidence of 
pressure upon the embryo until centripetal wall formation occurs in the 
endosperm, after all parts of the embryo have become well established 
(4, P- 433). 
The first divisions of the zygote give rise to a filament of three, occa- 
sionally four, cells (figs, i, 2, 3). Then transverse divisions and vertical 
walls occur in the terminal and subterminal cells of the row (fig. 4). The 
lowest cell is primarily concerned in the formation of the suspensor, which 
is unicellular or divided at the top by one to three more or less oblique 
walls (figs. 5, 9). The embryo proper develops as an ovoid mass until it 
has attained a length of 8-10 cells, when it becomes evident that the struc- 
ture is no longer radially symmetrical, but that it has developed a bilateral 
symmetry, one side being more convex than the other (figs. 5, 6, 7, 8). 
All the tissue beyond the point of indentation becomes the cotyledon, Avhich 
seems to be derived from the end cell of the primitive row. It seems equally 
clear that the root is derived from the middle cell, but the conditions in 
the region of the growing point are not so certain. The swelling on the 
lower portion of the indentation gives rise first to 'an outer ridge that con- 
nects with the cotyledon on the sides, and subsequently, within and pro- 
tected by this ridge, to a series of 2 or 3 plumular leaves (figs. 9, 10, 11). 
The first sign of the development of the vascular system appears at the 
same time as the first plumular leaf, in the form of a pair of bundles in the 
cotyledon (fig. 13). These soon join with the rudiment of the axial system 
at the cotyledonary node. In the old embryo this node has four principal 
poles, two connected with the bundles which traverse the cotyledon, two 
with bundles which run forward and curve up, joining with the main cotyle- 
donary traces above the tip of the plumule. These loops first appear near 
their attachment at the node, and subsequently effect union with the main 
trace (figs. i6, 17, 19). The rudiment of a single bundle appears in the 
older plumular leaf before germination (figs. 18, 20). As the size of the 
embryo increases, the ridge early formed connecting the edges of the coty- 
ledon elongates and widens, forming with the cotyledon a short sheath 
around the plumule. The base of the cotyledon becomes quite broad and 
curved so that the looped bundle traces appear in a transverse section to 
