CONTRIBUTIONS TO BOTANY. 
169 
longitudinal woody threads are observed, which are the fila nu- 
tritoria of Mirbel and St. Hilaire, containing the nourishing 
vessels that originally supplied the placenta, and these are now 
traceable from the point of attachment of the ovules down to 
the base of the central vacant space, and into the peduncle. 
I have examined the matured seed, in a fresh as well as dried 
state, and find exactly the same development, only that all the 
parts are now grown to double the last-mentioned proportions. 
It commonly occurs here that two osseous cells become perfected, 
and remain contiguous to one another upon one side of the bony 
endocarp, each containing a ripe seed ; the third cellule is usu- 
ally obsolete and membranaceous, while, as in the former case, 
all trace of the fourth cellule disappears : the nourishing threads 
of the extended placenta are here distinguishable in the position 
above described. The seeds, in the several instances examined, 
were either suspended or erect in the respective cells, according 
to the original position of the ovules from which they were per- 
fected. In Stijrax the testa is thick and osseous ; in Halesia it 
is thin and membranaceous, and often somewhat adherent to the / 
osseous cellule, but it is extracted without difficulty, and, when 
dry, is of a dark colour, smooth, thin, and of a somewhat char- 
taceous texture, with a very prominent, adhering, external, simple, 
cord-like raphe, proceeding from the hilar point of its attachment, 
and extending along its ventral face to its opposite chalazal ex- 
tremity, in a line corresponding with the nourishing threads 
before described, and facing the original axis of the })lacenta : 
the inner integument is a delicate transparent membrane that 
closely invests the albumen ; and at its extremity, opposite to 
that of the hilum, it has a small well-marked chalaza, under the 
form of a coloured transverse line ; at the opposite extremity or 
radicular end, 1 have always found a distinct, dark-coloured, 
free, adpressed thread, which is easily raised by a point ; it is a 
suspensor : the albumen and embryo quite accord with the de- 
scriptions of Gaertner and DeCandolle. It may be remarked 
that the radicular end, with its suspensor, is sometimes superior, 
at other times inferior, owing to the reason before assigned. 
I uill add a few words respecting the development of the en- 
tire fruit. The caljTC, in its young state, has eight prominent 
external nervures, of which four are opposite to the incomplete 
cells of the ovary, and terminate in the points of the teeth of the 
border, the other four alternating with the calycine segments ; 
these last, with the growth of the ovary, acquire a considerable 
increment, producing, in Halesia tetraptera, four long, broad, 
corticated wings, and in H. diptera, only two opposite bi’oad 
wings, the two alternate ones being much narrower ; these wings, 
in the ripe fruit, are thickened considerably towards the peri- 
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