AVICINNIA. 19] 
The embryo sac Fig. I. when mature is curved within the 
point of the nucleus in the shape of a retort, or shepherd’s 
crook, The line of the axis corresponds rather with the longer 
extension backwards, the recurved points however corresponds 
with the axis of the ovulum, appearing as if it were going 
to meet the fascicle of vessels that is to be found in the up- 
per 3 at least of the central denser tissue of the ovulum. 
It is within the curve that all the changes take place, Ist 
inthe formation of albumenary tissue, sometimes without 
application of boyaux, the long extension backwards and 
the recurved apex remaining unchanged the boyaux appear 
to pass into the crook, to a considerable depth nearly to the 
base of the recurved unchanged apex, they here appear oós- 
curely to form the rudiments of a cellular mass, which is the 
future embryo, but is exceedingly indistinct, all these may 
occur within the ovulum.* 
e albuminous mass enlarging forwards, soon protrudes, 
ànd rapidly assumes a considerable size. 
3 Its aspect is cellular, shape flattened roundish, then a curved 
line appears, an semper, on its outer surface, from which the 
cotyledons soon protrude. 
: This mass continues to increase, the lower part preserving 
ts thick, cellular appearance, the upper or that between 
the inner cotyledon and the nucleus becoming expanded, 
flattened, and cellular membranous. 
‘he cotyledons become conduplicate at a rather early 
period, subsequently the whole of the embryo except the 
x “cle is quite naked, that remains in its cavity in 
the fleshy base of the albuminous mass. Correspondingly, 
e Posterior extension passes back into the placenta where 
Comes dilated, and ramified, and exceedingly large. 
üt far as Ihave seen the recurved apex remains unchang- 
P to a latish period. Yet I have thought I have seen it 
Xa. 2 ? 
I think I have seen in one instance grumous matter in the sac with. 
355 attachment of boyaux. 
