26 
An objection may perhaps be started to this doctrine from the conside¬ 
ration of succulent and stony fruits; but these, in their early stage, have the 
same organization as Pericarps. 
We have an example of this in the pear and the mango;* and it may be 
observed, that the deposit of hard, woody, or stony particles, does not take 
place till a considerable time after the full formation of the embryo. Young 
filberts, or the walnuts which we use for pickles, are also very familiar ex¬ 
amples of the soft state of the early shell. 
The woody shell may therefore be considered as a true pericarp ;§ and, 
as the manner in which the kernel is able to escape from its enclosure is a 
matter of no small wonder to the contemplators of nature, it certainly de¬ 
serves our present consideration. 
For the escape of the seed, the hard shell, acted on by heat and moisture, 
and the rarefaction of the air within, and force of the struggling embryos, 
endeavouring “ to burst their cearments,” opens “ its marble jaws,” and this 
with a facility exceeding common apprehension. 
For this purpose shells are like pericarps, which first seem of one valve, 
one entire piece, scarcely shewing even a line of separation, and then divide, 
as the occasion requires, into several different compartments, or pieces, but 
more usually into two, which might be conjectured from observing the na¬ 
tural division that takes place in walnuts, apricots, and other stone fruits. 
Where there is neither pericarp, nor shell, for some plants are found 
actually to bear naked deedj (Semina Nuda), the calyx% then serves the 
office of pericarp, and increases with the growth of the embryos, and so in¬ 
volves them, as not unfrequently to be mistaken for real pericarps. 
The ramifications of the vedteU in the leaflets of the calyx may be made 
apparent by maceration in water, as the skeleton of other leaves are produced; 
and their conjunction with the receptacle of the seed is then very evident. 
AYhen the seed has been liberated from its foldage, water enters by the 
aperture , or foramen, before mentioned, and insinuates itself between the 
* Vide the Plate representing some preparations in the superb collection of Mr. Heaviside. M }t> 
§ Vide note p, page 20. 
, i Th ^ Ca, y x 1S reckoned one of the parts of fructification, and will be explained hereafter. It has 
a double office the protection first of the flower, next of the fruit, and it sometimes, as shewn above, 
performs the office of placenta, in lieu of the Pericarp. 
