BITTER ORANGE 



93 



Description. The ovary of the orange tree is superior and poly- 

 carpellary ; it is composed of eight (or sometimes more) carpels, each 

 containing two rows of seeds with axile placentation. During the 

 growth of jthe ovary the loculi increase in size, and the outer wall 

 (pericarp) in thickness. Into the loculi there grow from the inner 

 epidermis of the pericarp numerous hair-like processes which fill with 

 juice and completely occupy the loculi ; they form the pulp contained 



FIG. 53. Orange peel. D, transverse section, enlarged 

 100 diam. ; I, oil-glands. (Berg.) 



in the ' quarters ' of the orange, the thin membrane enclosing each 

 quarter being the endocarp. The fruit is a variety of berry sometimes 

 termed ' hesperidium.' 



The bitter orange may be distinguished from the sweet orange by 

 its rougher and usually darker rind and sour, bitter pulp. The rind, 

 which is agreeably aromatic and has also a bitter taste, shows, when 

 cut transversely, a narrow yellow outer part corresponding to the 

 epicarp, in which large oil-glands are discernible with the naked eye, 

 and an inner white portion corresponding to the mesocarp. 



The peel is used both fresh and dried. In cutting it from the fruit 

 care should be taken not to rupture the oil-glands more than is 

 necessary, for it is to the volatile oil they contain that the pleasant 



