LEMNA. 217 
tween the inner coat and the nucleus. The base of the 
testa which is thick, becoming more and more opaque, appa- 
rently from its cellular tissue containing air. No other 
changes than those of change of figure and size occur for a 
long time, except іп the nucleus which is rapidly excavated 
and at length assumes the form of a membranous sac. 
At the time of impregnation, the ovula is somewhat cylin- 
drical, with a somewhat conical apex and a sub-dilated base, 
the testa isthick and fleshy, particularly its apex, the inner 
coat is also thick, and contains the nucleus, which although 
not separable, has every appearance of being a membranous 
sac rupturing on slight pressure. 
Somewhat later the ovula has much the appearance of a dice- 
box with a conical lid, the secundine has become elongated 
and thinner, and its apex has commenced to assume a conical 
form, in which however no radicle cells are visible, the nu- 
cleus is correspondingly elongated but, still preserves its sacci- 
form appearance. 
The next stage at which I have examined it, is immediately 
antecedent to the full development, the seed is now an irre- 
gular oblong and truncate angular body, with a short thick 
and smooth funicle, the testa is greenish fleshy thick and 
rugose externally, its apex is somewhat radiately rugose, de- 
pressed towards the centre which is very thin, and elevated 
into an obscure point; to this the conical fleshy apex of the 
inner coat, which is now reduced to a membrane, corres- 
ponds. This is filled by the albumen, scarcely yet solidified. 
Ihave not ascertained the existence of the nucleary mem- 
brane. The albumen із of course ? developed in the embryo- 
nary sac. The embryois at this period to be found in the neck 
of the albumen which is short, it is obturbinate or obovate, 
cellular with a broad attachment. The lateral fissure is very 
distinct, corresponding to the obscure rounded, cellular plu- 
mula. The younger the state, the more developed is the 
fissure. е 
The only anomaly consists in the early adhesion of the 
c 2 
