CONTRIBUTIONS TO BOTANY. 
241 
but it runs along the lateral edges opposite the margins of the 
cotyledons, as in the Colletiea ; and we find here some points of 
structure deserving of being recorded. The outer corneous 
covering of the seed is entire, as in the Colletiece, but much 
thinner in textm’e, and more translucent. This coating is of a 
more compressed form, tapering towards the base, which is 
polished and somewhat tumescent, and which has a basal chink 
similar to that of the CoUetiece, through which the nourishing 
vessels of the raphe pass from the placenta. It may here be 
observed, that in the bottom of each cell of the nut is seen a 
small fleshy cup, with a crenulate raised border, within which the 
seed is seated, and across the bottom of this cup is a white raised 
line, corresponding to the hollow in the basal chink of the seed ; 
but the margins of this chink and the tumid base of the external 
coating are highly polished, and the latter shows no sign of any 
organic connexion with the cup : the hilar point of attachment 
is therefore confined to the mere cord of vessels proceeding from 
the placenta to the raphe. The second tunic, which is very thin 
and membranaceous, does not quite fill the cavity of the outer 
shell ; it is more conical at its base, where it terminates in a 
short thread that issues through the chink above mentioned; 
the space between it and the outer shell is filled with a quantity 
of very lax white cellular tissue ; it is pyriform in shape, much 
compressed, and tapers into a short cord at its base, which is 
seen to divide itself into two prominent threads that run along 
the margins of the tunic, and meet over a large fleshy chalaza- 
like disk in the apex, in one uninterrupted line : this cord of 
vessels is therefore completely peripherical, as in Colletia. This 
second tunic is quite free from a third, inner integument, which 
is thicker and more opake, and which invests a very thin fleshy 
albumen ; this third integument is sensibly shorter, and more 
conical at its base, where it terminates in a dark areolar neck, 
and tapers into a short suspensor-like thread, which is embraced 
by the neck of the second tunic. These two integuments are 
easily separable from one another by the introduction of a needle 
between them, except round the margin of the apical chalazal disk, 
where they appear to be intimately agglutinated ; the embryo is 
flat and compressed, its foliaceous cotyledons being parallel with 
the partition of the nut, and their margins contiguous to the 
peripherical cord of the raphe. This organization* is more 
evidently seen in this instance, as the seed is six times longer 
than that of Colletia, which it greatly resembles in structure : 
it is also remarkable for exhibiting many points analogous 
* Drawings of the above analysis will be given in Plate n in this 
volume. 
2 I 
VOL. I. 
