94. 



HISTORY OF THE VEGETABLE KINGDOM. 



three parts of the pericarp are extremely distinct 

 from each other, and the endocarp is here evi- 

 dently under the fonn of a mere membrane ap- 

 plied upon the internal surface of the sarcocarp. 

 But, shortly after, we see the part of the sarco- 

 carp nearest this inner membrane gradually be- 

 coming whiter and denser, and passing through 

 all the intermediate stages, before acquiring the 

 bony solidity which it presents at the period of 

 maturity. Nofv, in this case, although this 

 portion of the sarcocarp is intimately united and 

 confounded with the endocarp, it cannot by any 

 means be referred to the latter, but belongs to 

 the sarcocarp, as it is really formed by it. The 

 shell, or the bony part which is found at the centre 

 of the peach, is therefore formed by the endocarp, 

 to which is joined an ossified portion of the sar- 

 cocarp. What we have here said of the peach 

 is equally applicable to the apricot, the prune, 

 the cherry, and the almond. Such are Richard's 

 views of the pericarp, but other botanists are 

 still disposed to consider the shell of such seeds 

 as distinct from the soft enveloping pulp. 



If we now take the fruit of the common pea 

 and analyze it, we find it to be elongated and 

 compressed so as to present two short edges, 

 along which run two longitudinal sutures. This 

 circumstance shows that, when ripe, it wiU open 

 in two segments or valves. It is, therefore, a 

 bivalve pericarp. On cutting it longitudinally, 

 we find only a single internal cavity, containing 

 from eight to ten seeds. Thus it is unilocular 

 and polyspermous. The seeds are all fixed, along 

 the upper suture, to a small thick margin, run- 

 ning along the suture, and giving off a distinct 

 prolongation to each seed. All that occurs ex- 

 ternally of the seed forms part of the pericarp. 

 At the outer surface is a thin membrane, which 

 adheres closely to the adjacent part : it is the 

 cpicarp. The internal cavity is lined by another 

 membrane, not quite so closely adhering : it is 

 the endocarp. The fleshy, green, and vascular 

 part, which is observed between these two mem- 

 branes, although of no great thickness, is the 

 sarcocarp. The small longitudinal pi-ominence 

 which runs along the suture, and to which the 

 seeds are attached, is the trophosperm. Each 

 little prolongation connecting a seed with that 

 body is a podosperm. 



We thus see that the pericarp is the part of 

 the fruit which forms the walls of the simple or 

 multiple cavity in which the seeds are contained : 

 that it is always composed of three parts: \st. 

 The epicarp, or membrane by which it is covered 

 externally ; 2dfy, The endocarp, or internal par- 

 ietal membrane lining its internal cavity ; Sdfy, 

 A more or less thick and fleshy part, which, 

 however, is sometimes thin, and not easily per- 

 ceived, but always vascular, and which is named 

 the sarcocarp or mesocarp; and that the pericarp 

 is often divided internally by partitions into a 



greater or less number of cells, when it is called 

 lilocular, trilocular, quadrilocular, multilocular, 

 &c. The point of the cavity of the pericarp 

 to which the seeds are attached presents a fleshy 

 prominence, of variable size, coming off from 

 the sarcocarp, which has received the name of 

 trophosperm. The podosperm, again, is the little 

 process of the trophosperm which supports the 

 seed. When the trophosperm or the podosperm 

 cover the seed, so as to embrace it over a con- 

 siderable extent, the peculiar prolongation by 

 which this is effected bears the name of arillus. 



Fruits, considered in a general point of view, 

 have been divided in various ways, and have re- 

 ceived particular names. Thus, the name of 

 simple fruit has been given to that which pro- 

 ceeds from a single pistil, contained in a flower; 

 of which kind is the peach, the cherry, &c. A 

 multiple fi'uit, on the contrary, is that proceed- 

 ing from several pistils contained in the same 

 flower : for example, the rasp, the strawberry, 

 the fi-uit of the genera ranunculus, clematis, &c. 

 Lastly, the name of compound fruit is given to 

 that which results from a greater or less num- 

 ber of pistils placed close together, and often 

 united, but all coming from distinct flowers sit- 

 uated very near each other ; as in the mulberry. 



According to the nature of their pericarp, 

 fniits are distinguished into drt/ aai fleshy. Dry 

 fruits are those whose pericarp is thin, or formed 

 of a substance generally containing little juice. 

 Fleshy fruits, on the contrary, have a thick and 

 succulent pericarp, and their sarcocarp in parti- 

 cular is very large. Of this kind are melons, 

 peaches, apricots, &c. Fruits may remain en- 

 tirely closed in all parts, or may open into a 

 determinate number of pieces named valves. 

 From these circumstances, theyare distinguished 

 into dehiscent and indehiscent. The latter, when 

 they are dry, are also named capsular fruits. 

 According to the number of seeds which they 

 contain, they are divided into oliffospermous and 

 polt/spermous. Oligospermous fruits are those 

 which contain only a small number of seeds, 

 which, in most cases, is precisely determined : 

 whence the epithets monospermous, dispermous, 

 trispermous, tetraspermous, pentespermous, &c., 

 applied to the fruit, to denote that the number 

 of its seeds is one, two, three, four, five, &c. 

 Polt/spermous fruits are all those which contain 

 numerous seeds, the precise number of which it 

 is unnecessary to determine. 



The form and stracture of the pericarp, being 

 so various in different plants, botanists have 

 found it extremely difficult to arrange them 

 under any systematic classification; the following 

 distinguishing forms, however, can be always 

 recognized : the capsule, the pome, the berry, 

 the nut, the drupe, the silique, the legume, and 

 the cone. 



The capsule is a drj-and membranaceous peri- 



