IN FLOWERING PLANTS. 207 
and free, and evidently presents the nearest route for the pas- 
sage of the boyaux. Pi. 56, A. figs. 1, 2, 3, also pl. 55, L. 
figs. 1, 2. Long before exponi 
At a very early stage they are reduced to primine and 
secundine : the orifices of both which are on a level. 
The nucleus is a subsequent? development, and arises 
from the base of the cavity of the secundine. See pl. 56, B. fig. 
4. It soon presents traces of an internal cavity. 
Just before expansion the coats of the ovule have become 
narrowed towards their openings. These are very distinct. 
that of the secundine projecting beyond: that of the primine. 
The nucleus being entirely included: it is at this period an 
empty sac. See pl. 56, C. figs. 1, 2, 3. 
Very probabiy this is erroneous : in all others the nucleus 
is co-existent: if this be so here, the primine is reduced to 
a mere rim, See pl. 55. L. fig. 2. c. 
All the ovula of one torus have not the same development, 
the secundine being in some shorter than the primine. 
After expansion, but previously to impregnation, the apex 
of the primine has become elongated, and is now nearly on a 
level with that of the secundine. The nucleus still remains 
an empty sac. 
During impregnation, the mouth of the primine has con- 
tracted, that of the secundine being but very little exserted. 
Pl. 56, F. fig. 1. a. 
The apex of the nucleus becomes of a brownish colour. 
Shortly after impregnation, a central cavity is visible in the 
nucleus, the parieties of the sac or cavity being most dis- 
tinct towards the apex of the nucleus, becomes more and 
more indistinct towards the base. See pl. 56, A. [when is this 
cavity first visible ; Re-examine again the first appearance of 
the vitellus.] At the apex of this a vesicle is visible, attached 
to the apex of the nucleary cavity by one of a much smaller 
` size. "This is the first rudiment of a quartine. As the deve- 
lopment proceeds, the quartine enlarges, becomes cellular, 
and extends downwards, pushing before it the substance of 
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