136 VEGETABLE ORGANOGRAPHY. 



pium) ; like the lower surface of the leaf, it frequently 

 bears hairs, glands, and stomata, and presents in most 

 cases a decided analogy to the part of the leaf to which 

 it corresponds. 



2d. The inner surface, which represents the upper 

 part of the leaf, is a membrane to which Richard has 

 given the name of Endocahp ( Endocarpium) ; its inter- 

 nal position, preventing its exposure to the air and light, 

 causes it to differ more than the epicarp from the 

 corresponding part of the leaf. Sometimes it appears 

 under the form of a fine membrane, foliaceous and even 

 greenish, as in the Pea ; sometimes under that of a fine, 

 pale, and as it were, etiolated membrane, as in Asclepias; 

 this membrane sometimes becomes thicker, and some- 

 times even hard and bony, as in the Peach, and then it 

 forms the stone of the carpel. All the intermediate 

 states between those which I have mentioned are found 

 in various fruits. 



3d. Between the Epicarp and Endocarp is found the 

 plexus of fibres, vessels, and cellular tissue, which con- 

 stitutes the body of the leaf or carpel, representing the 

 mesophyllum of the former ; it has received the name of 

 Mesocarp (mesocarphcm). Sometimes it is very thick 

 and fleshy, as in the Peach, or Cherry, and then the 

 name of Sarcocarp, or more commonly, that of the 

 Flesh (caro) of the fruit is given to it. Sometimes it 

 is thick, but dry and fibrous, and then it is called the 

 Husk, as in the Almond. Sometimes it happens that 

 the epicarp and endocarp separate during their growth, 

 and leave between them an empty space, in which are 

 still observed traces of the fibres of the mesocarp ; this 

 rare and singular organization is seen well in Cysti- 

 capnos Africana. Sometimes it is also distinct, but less 

 thick and more foliaceous, as in the Bean and Pea ; at 

 times it is so thin, that it cannot be easily distinguished 



