CLASSIFICATION OF FKUIT3. 83 



epidermis of the leaf ; s^sarcocarp^ih^ middle, Fi-.93. 



representing the parenchyma- of the leaf; 7i, en- 

 docarp^ equivalent to the upper epidermis of the 

 leaf; sd represents the dorsal suture ; ^t^, the 

 ventral suture ; </, a seed. In the cherry and 

 plum, the sarcocarp is the part of the fruit 

 which is eaten. In the almond the seed or pu- 

 tamen is used as fruit, while its leathery covering, 

 or sarcocarj^, and the hard epicarp, are reject- 

 ed. The pulpy matter found in the grape and 

 gooseberry is formed from the placenta, and is not the sarco- 

 carp. 



1). The external pieces^ which form the sides of the seed- 

 vessels, are called valves. If a pericarp is formed of but one 

 valve, it is imivalved ; the chestnut is of this kind. A pericarp 

 with two valves is said to be hivalved^ as a pea-pod. The peri- 

 carp of the violet is trivcdved j that of the stramonium quadri- 

 valved. Most valves separate easily when the fruit is ripe ; this 

 sej^aration is known by. the term dehiscence. Sutures^ or sea^ns, 

 are lines which show the union of valves ; at these seams the 

 valves separate in the mature stage of the plant : they are very 

 distinct in the pea-pod, which has two sutures. Partitions.^ or 

 dissepiments.^ are internal membranes which divide the pericarp 

 into different cells : these are longitudinal when they extend 

 from the base to the summit of \\iQ> pericarj^ ; they are trans- 

 verse when they extend from one side to the other. Column.^ 

 or columella^ is the axis of the fruit ; this is the central point 

 of union of the partitions of seed-vessels ; it may be seen dis- 

 tinctly in the core of an apple. Cells are divisions made by 

 the dissepiments, and contain the seeds ; their number is seldom 

 variable in the same genus of plants, and therefore serves as an 

 important generic distinction. Receptacle of the fruit is that 

 part of the pericarp to which the seed remains attached until its 

 perfect maturity ; this organ, by means of connecting libers, 

 conveys to the seed, for its nourishment, juices elaborated by 

 the pericarj). Some plants are destitute of a pericarp, as in the 

 labiate flowers, compound flowers, and grasses ; in these cases 

 the seeds lie in the bottom of the calyx, which performs the 

 office of a pericarp. 



Classification of Fruits. 



88. " The most scientific and natural method of classing fruits," says Mirbel, 



"would be to distribute them according to the vascular structure of pericarps and 



seeds, employing as secondary characters only tlie succulence or dryness of the tissue, 



or the indeliiscence of pericarps. The student would then perceive tliat the fruita 



- •* 



h. Valves— Sutures— Partitions or flissspiments— Column— Cells— Receptacle of tlie fVu it— Pericarp 

 sometimes wantin'?.--.-^^. Remarks from Mirbel respecting the classification of (ruits. 



