116 BOTANICAL GAZETTE [AucusT 
growing in the open found the anthers nearest the ovary to have 
shed their pollen. Material collected at the same locality two days — 
later was found to show fertilization. The time of pollination of — 
the particular flowers gathered and fixed may have been as much — 
as five days before gathering, but was probably not earlier. 
The thin-walled slender pollen tubes may be found in abundance — 
about the mouths of the micropyles, often forming considerable — 
masses. The cells which line the micropyle are heavy-walled and 
of such darkly-staining contents that it is difficult to observe the 
pollen tube within the micropyle, and indeed the entrance of the 
tip of the tube, with the nuclei, was not observed. The synergidae 
become appressed to the wall of the sac. The end of the tube upon 
entrance to the sac becomes expanded and pushes downward to 
one side of the egg. The generative nuclei have lost the elongated 
shape they were seen to have while passing down the style and have 
become spherical. Fusion of the first generative nucleus shows 10 — 
special peculiarities (fig. 38). 
ENDOSPERM. . 
The fusion of the polar nuclei is quickly followed by division. 
The first wall in the endosperm is transverse to the length of the sac 
and divides it into equal halves (fig. 39). The daughter nuclei — 
divide in like manner (fig. 40), as do also the grandaughter nude), 
giving rise to an endosperm of eight cells in linear series, in which 
the walls are all transverse, although not uncommonly somewhat 
oblique (fig. 41). Subsequent divisions are less regular, and by thé 
time the fertilized egg has divided the endosperm contains approx 
mately 150 cells, its base having used up the nucellus either com™ : 
pletely or all but a half dozen cells (fig. 42). At this time the endo 
sperm cells are highly vacuolated and the laying down of food has 
not begun. 
The relative rate of development of the endosperm in ovules upo? — 
different parts of the same placenta is the same as was noted with 
regard to the integuments. An ovule at the point of juncture of 4 
the adjacent lateral placental outgrowths may have an eight-celled . 
endosperm at the same time that the endosperm nucleus has not 
yet divided in an ovule upon the edge of the placenta nearest the 
main placental outgrowth. 
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