162 BOTANICAL GAZETTE [waRcr 
Ranunculacee*s is doubtful, but there is little question that the 
early divisions are karyokinetic, and each division is followed 
by the formation of a division-wall. 
The upper endosperm cells are usually decidedly larger than 
those which are in contact with the antipodal cells, but otherwise : 
there is no marked difference between them. . 
As in the other aroids that have been studied, the upper pat 
of the nucellus persists as a sort of cap covering the apex of the — 
embryo-sac; the lateral tissue gf the nucellus, however, is com — 
pletely disorganized, so that the embryo-sac comes in close 
contact with the inner integument (figs. 15, 78). 
So far as my observations go, the species of Philodendrot, 
Anthurium, and Dieffenbachia examined agree closely with Lys 
chiton in the development of the embryo-sac, but as yet the | 
presence of such conspicuous antipodal cells has not been 
observed. In many cases noted (see fig. 18) the embryo-sas — 
at a very early period, becomes completely filled with large — 
celled parenchyma, in which it is impossible to recognize aly 
antipodal cells, nor in many cases can any certain traces of a0 
embryo be detected. It is hoped that a more thorough study | 
of these puzzling forms, which I expect to make soon, 
explain the meaning of these appearances. ! 
Except in Pistia, which has been carefully studied by Hegel- 
maier,* I have been unable to find any complete account of the 
development of the embryo among the Aracee. Hofmeistet 
gives figures of a few stages of a number of genera, but these 
are too incomplete to be of much value. A preliminary = ‘ 
ination of the embryo of Lysichiton indicates that it is of ee 
the same type as that of Pistia. Probably no suspensor is oe | 
oped, and the young embryo is very soon completely imbed a 
in the endosperm, recalling the appearance of the embry?" 
Isoétes (fig. 16). 
: The embryo finally completely fills the ripe see 
in many other genera, e. g., Anthurium, but in some 0 
*3 MOTTIER, Joc. cit. 
d, as it does 
f the aroids, = 
“ HEGELMAIER, loc. cit. 
