96 



HISTORY OF THE VEGETABLE KINGDOM. 



Acom. 



ezactly to tlie above definition or exceptions, 

 are regarded, however, by botanists as being also 

 varieties of tlie berry, such particularly as those 

 of the juniper and yew tree. In the former the 

 scales of the fertile catkin, which ultimately be- 

 come succulent, unite also together and form a 

 globular fruit, resembling a berry so much as to 

 have obtained the name. In the latter, the 

 calyx or receptacle, as it is generally believed to 

 be, which is at first a thin and scaly like sub- 

 stance, of a whitish or greenish complexion, 

 embracing merely the base of the ovary, expands 

 and enlarges into a thick and pulpy envelope, of 

 a bell shaped figure, and of a most beautiful red, 

 investing the whole of the ovary except the 

 mouth or open extremity, and giving the fruit 

 the appearance of a berry, as it is generally 

 called, though, strictly speaking, it is more pro- 

 perly a nut than a berry. 



The nut shell is a pericarp 

 of a hard woody texture, 

 though sometimes of the 

 consistence of leather ; it 

 rarely opens spontaneously, 

 or if it does so, it divides 

 into two valves only. The 

 Bcom and filbert are ex- 

 amples of the hard nut ; the 

 chestnut of the soft leathery. 

 In the genus eckium, the pericarp is crustace- 

 ous, and in myosotis as hard as flint. The figure 

 of the nut shell is generally spherical or oval, 

 sometimes it is angular. The acom is a 

 single celled fruit, and one seeded, in conse- 

 quence of the constant abortion of several ovules. 

 It proceeds from an inferior many celled and 

 many seeded ovary, of which the pericarp is in- 

 timately attached to the seed, and always pre- 

 sents at its summit the very minute teeth of the 

 limb of the calyx, and is in part contained in a 

 kind of scaly or leafy involucre, named the cup. 

 In trapa it is two celled, and in the chestnut 

 six celled, but the partitions are not perceptible 

 in the mature state of the fruit. The contained 

 seed or nut is generally denominated the nuc- 

 leus, and is extricated for the most part, by 

 means of a fissure, effected in the process of ger- 

 mination, or by the gradual decay of a part. 

 But in the walnut the shell opens spontaneously 

 into two valves, and in the filbert, in which it does 

 not perhaps open spontaneously, the valves seem 

 at least to be marked out by a sort of superficial 

 line, and are easily divided with the assistance 

 of a knife. In lycopsis it opens by a hole or 

 fissure at the base, and in trapa by a hole at the 

 apex. Sometimes it is naked, as in lycopsis ; 

 while in other cases it is coated or covered with 

 a membranous envelope, either wholly or in 

 part, as in the acom and walnut. 



The drupe is a soft and pulpy pericarp, with- 

 out valves, but inclosing a nut. It may be 



Cherry. 



exemplified in what is gen- 

 erally called stone fruit, as in 

 the cherry, the peach, the apri- 

 cot. It is generally round, as 

 in the cherry ; or elliptical, as 

 in the apricot. In the genus 

 helesia it is winged. Its sub- 

 stance is succulent, as in the 

 plum; or fibrous, as in the 

 cocoa-nut; or dry and leath- 

 ery, as in the almond, spar- 

 gcmium and gaura, which last are nearly alliea 

 to nuts. It opens for the most part merely 

 by accident or decay, but in the peach, and 

 perhaps a few others, it opens spontaneously. 

 The shell of the drupe is generally very hai'd, 

 whence the tenn stone fniit. But in some cases 

 it is soft and tender, asmstyraxcallapht/llum; in 

 some it is leathery, as in hypTienx; and in some 

 woody, as in cerbera. It does not, perhaps, in any 

 case open spontaneously, and yet there are some 

 shells in which the traces of valves may be dis- 

 cerned, as in that of elaeocarpus ; or in which a 

 division may easily be effected, by means of the 

 knife, as in prunus. Incomplete valves indeed 

 are sometimes found at the top of the shell, as 

 in nitraria and gaura, so as to make it resemble 

 a toothed capsule ; and in a few genera there is 

 an opening formed by means of a hole or pore 

 at the top, as in cocoa-nut. The figure of the 

 shell is very often elliptical or egg-shaped, but 

 compressed, assuming, however, a great variety 

 of modification, sufficient, in most cases, to deter- 

 mine species. Its surface is never quite smooth, 

 but often rough, and irregularly furrowed, as iu 

 the peach; in order, perhaps, that it might the 

 more closely unite with the exterior part of the 

 fruit. Sometimes the shell is separable into 

 several different divisions, each forming an en- 

 closed cavity, and containing a seed. In this 

 case each division assumes the appellation of a 

 pyrena, and the fniit is said to be deperenous, 

 treperenmis, or polyperenous, according to the 

 number of divisions into which it separates. 

 The partitions, however, as in the compound 

 nut, are effaced in the matured fruit. 



The silique or pod is a dry and elongated 

 perioai-p, consisting of two valves with two op- 



