1895.] Embryology of the Ranunculacee. 297 
each initial cell, the upper being already partly disorganized. 
The development of the embryo-sac from the mother-cell is 
perfectly normal. In this species the egg-apparatus is larger 
at first than the antipodal cells (fig. 40) two of which only are 
shown in the figure. The latter increase in size, however, 
with the subsequent growth of the embryo-sac, but as far as 
observation went, they do not reach the enormous size that 
obtains in the genera previously mentioned. 
Ranunculus recurvatus.—The most striking difference be- 
tween R. abortivus and R. recurvatus from an histological 
point of view, is the larger meristematic cells of the latter. 
In this respect R. recurvatus resembles Delphinium and Cal- 
tha. The development of the embryo-sac from the initial 
cell requires but few additional remarks. Figs. 42 and 43 
will make the process clear. Fig. 44 presents a phenomenon 
probably indicating the tendency of more than one cell to de- 
velop into an embryo-sac. 
The antipodal cells are large, and increase considerably in 
size during the subsequent growth of the sac. In one case 
their position differed from their usual orientation (fig. 45). 
In one embryo-sac a cleft or cavity seemed to extend some 
distance downward into the chalaza beneath the antipodal 
cells, in which could be recognized only a slight trace of a 
Protoplasmic substance (fig. 46). Here the large antipodal 
cells, rich in protoplasm, and with large nuclei, rest upon the 
disorganized remains of cells. Another exceptional phenom- 
enon was observed in the presence of a small tracheary and 
a small tracheid element beneath the antipodal cells (fig. 60). 
In this figure are shown two antipodal cells of unequal size, 
one behind the other, with an endosperm nucleus on the right 
and left, and the above named elements below. As these 
two phenomena were observed in one case only, I am not in- 
‘clined to attach any special significance to them at present. 
R. septentrionalis.—This species resembles the preceding 
very closely, especially in regard to the size of its embryonic 
cells and the behavior of the initial cell, which gives rise 
Sometimes to four cells (fig. 47). Fig. 48 illustrates what 
frequently takes place in the cells which immediately sur- 
round the embryo-sac mother cell and its disorganizing sister 
Cells. The mother-cell in the figure is partly concealed by 
those on either side. 
20—Vol. XX.—No. 7. 
