160 
CONTRIBUTIONS TO BOTANY. 
divided by three (in Halesia by four^ and in Pterostyrax by five) 
short partitions, which unite with the central placenta, and, 
under the form of prominent parietal nervures, are continued up 
the wall of the ovary to near its summit, which always remains 
unilocular; but neither these nervures nor the margins of the 
short partitions of the basilar incomplete cells exhibit any ovules. 
The abbreviated central placenta is thick, fleshy, and ovuligerous, 
bearing frequently more than thirty ovules, that is to say, ten or 
twelve in each division, arranged in three or four rows, its sur- 
face being corrugated by as many fleshy projections imbricated 
on one another, and between which the ovules are imbedded to 
some depth : this process is not, however, observable in Halesia. 
Nothing approaching this structure exists in Symplocacece. From 
these facts we may conclude that the normal condition of the 
component carpels in Styracea is that their margins are never 
placentiferous, and do not unite in a solid axis, and consequently 
are never continuous or connected with the style ; and the in- 
ference, in a theoretical point of view, is that the origin of the 
central placenta is due to the union of the petiolar bases of the 
hypothetical carpellary leaves in one common centre, where they 
are ovuligerous, their margins, as above shown, being barren. 
If we follow those botanists who have more or less adopted 
the system of arrangement planned by Jussieu, of distributing 
the difiFerent families of plants according to the normal struc- 
ture of the ovary, the Styracete ought to find their position 
near the Meliacece and Humiriacece, as originally suggested by 
that learned botanist, that is to say, among those families where 
the dissepiments of a polycarpellary ovary are incomplete in their 
summit, the placentary axis being unconnected with the style. 
Upon the same ground that I endeavoured to separate the Ica- 
cinacece from the Olacacece, so should the Symplocacece be removed 
from the Styracece. Pursuing the same rule, the Symplocacece, 
from the structure of their ovary and other leading features, will 
be found to range near the Alangiacece, Cornacece, and Hamame- 
lidacece, to which they bear the same relation that the Icacinacece 
have to the Aquifoliacece. This position will be seen to be very 
near that assigned to this family by the great Jussieu. 
These conclusions are further strengthened by pursuing the 
comparison of the relative struetures of the fruit and seed in the 
two groups under consideration. In Symplocos the fruit is a 
fleshy inferior drupe, crowned by the persistent toothed rim of 
the adnate calyx ; it encloses a hard bony nut, which is generally 
fii^- celled, rarely (by abortion) three-, two-, or one-eelled ; only a 
single seed is perfected in each cell, and this is long, cylindrical, 
and suspended from its summit ; its integuments are thin and 
membranaceous, and its copious albumen encloses a narrow, 
