, 
346 Mr. A. Henfrey on the Progress of Physiological Botany : 
nuclei seu nuclei). The orifice of the latter is directed toward the 
base of the pro-embryo. 
“ Before the formation of the nuclear papilla, there arises at the 
bottom of the cavity for the embryo-sac a minute transparent 
cell, the embryo-sac. This is seated like a tubercle on a parti- 
cular point as its suspensor. Already at this period we find in 
the cavity containing the embryo-sac from two to five, or even 
more free spiral filaments, never inclosed in their cellules. For 
at this period the spiral filaments move by the help of their cilia 
from the burst spiral-filament organs to the cavity for the em- 
bryo-sac, and penetrate into it. In this motion they are assisted 
by the mucus evacuated with them, and by the moisture always 
present on the under side of the pro-embryo. It requires some 
acquaintance with the form and different positions of the spiral 
filaments to recognise them in the cavity. The still wide open- 
ing of the cavity at this period facilitates their entrance (the 
borders of the organ scarcely project yet above the surface of the 
frond). At this period of the impregnation it sometimes hap- 
pens that we notice a quantity of dead spiral filaments around 
the cavity of the nucleus; they then appear curved like an S, or 
else wound circularly or spirally. But I have seldom observed 
this phenomenon. As the embryo-sac grows and thus displaces 
the spiral filaments, the canal of the papilla of the nucleus is 
formed, in the manner above described, and receives into it one, 
two or more, rarely several of them ; the rest decay in the bottom 
of the cavity. Before their entrance into it they exhibit with ad- 
vancing growth an evident expansion, which occurs especially in 
those subsequently received into the canal. In the mean time 
the embryo-sac, filled with blastema, has produced in its interior 
a parenchyma composed of several cells (endosperm), appears 
green, and has advanced so much in growth that it almost fills 
the cavity in which it is contained. One of the spiral filaments 
penetrates by one end into the part of the embryo-sac turned 
toward the canal. The penetrating end is that at which the 
smaller enlargement exists, which at the same time exhibits a 
greenish tint ; the larger, clavate, granular end projects out into 
the canal; this usually incloses a minute pyriform cellule. An 
obstacle of no slight importance interferes with the observation 
here also ; the delicate filiform connection of the two ends of the 
spiral filament is usually torn by the pressure of the covering 
glass upon the preparation, and thus we see only the separated 
ends, one in the canal, the other in the cavity for the embryo- 
sac, totally unconnected. As soon as the smaller expansion has 
reached the middle of the embryo-sac, it separates from the 
spiral filament and now forms a closed globule, the germinal 
