CONTRIBUTIONS TO BOTANY. 
261 
three abortive cells ; the seed is here fixed above the middle 
of the cell, with a conspicuous descending raphe terminating 
in the basal chalaza. Myxa will make a good genus com- 
posed of several species, only a comparatively small portion 
of the 122 species classed in the section Myxa by De Candolle. 
Cordia might conveniently be divided into several genera, 
for which good difterential characters now exist. The form and 
{estivation of the calyx have already served for sectional divi- 
sions ; but those of the corolla have been little attended to. 
Prof. De Candolle has noticed that the border of the corolla is 
campanulate and plicated convolutely in Varronia^ as in the 
Convolvulacece • in C. decandra^ Hook. & Arn., and C. angio- 
carpa^ Rich., the stamens are twice or three times the usual 
number, and the lobes of the corolla, which are equally nu- 
merous, have a contorsively imbricated {estivation : in some 
species the border is corrugated, but in general the lobes 
of the border are quincuncially imbricated, in aestivation. It 
has not been noticed that in all the species forming the section 
Gerascanthus the border is cleft to the base into five equal 
flat lobes, which in aestivation are folded sinistrorsely, as in 
Echites : this generic name, established by P. Brown, might 
therefore be restored. The section RhahdocaJyx has one lobe 
of the border external in aestivation, while the other four are 
convoluted. The characters of the stamens and fruit afford 
other good indications. Besides the features I have men- 
tioned as distinguishing Myxa^ may be added that of its 
polygamous or monoecious flowers. Cordia^ indeed, stands 
in much need of a thorough careful examination and redistri- 
bution. 
There is one point deserving of notice — that, from some un- 
known cause, it rarely happens in Cordia that more tlian one 
ovule becomes fertilized ; and this occurs equally in the plants of 
the Old and New World. The drupaceous nut is usually more 
or less gibbous and one-celled, with the seed attached as above 
described, in which case the abortive cells are generally seen 
on the flattened side, above the middle. May this almost 
constant abortion be owing to a defect in the stigmata, or to 
the puncture of insects, attracted perhaps by the nectariferous 
gland ? I have seen cases where the flowers on a branch ap- 
peared quite perfect, but there was hardly one ovary in the 
whole that had not been attacked by a minute grub. 
On a future occasion I will call attention to a new group of 
plants (the Auxemmacece) , closely allied to Cordiacece^ distin- 
guished by the great augmentation of the calyx in fioiit, l)y 
the peculiar aestivation of the corolla, and by its atropous 
ovules and seeds. 
