1 64 Fruits and Fruit- Trees. 



petiole a very curious condition, and well worthy of 

 observation by the student. The petiole itself is often 

 remarkably dilated. In all the species the leaves are 

 densely charged with oil-cysts. In all, the flowers, about 

 an inch and a half across, consist of four or five free petals, 

 either of a pure cream-white, or white flushed externally 

 with purple or violet, and more or less conspicuously 

 dotted with oil-cysts. The stamens, also free, vary in 

 number from ten to sixty, and are irregularly polyadel- 

 phous; the ovary within supports a thick green style, 

 crowned by a thick yellow stigma. The peculiarity of 

 the fruit consists not alone in its being juicy, as opposed 

 to fleshy. The juice is lodged in innumerable little bags, 

 irregular in shape, and which must be regarded as peculiar 

 cellular extensions of the faces of the carpels. The latter 

 vary in number from seven to about fifteen. The rind, 

 except in the tropics, where it is often grass-green, is 

 always some shade of yellow, internally spongy, almost 

 destitute of juice or sap of any kind, but covered on 

 the outside with a layer of different substance, which 

 again is charged with cysts of volatile, fragrant, and very 

 inflammable oil. 



Technically, this very curious type of fruit, occurring 

 in no other family, is called the " hesperidium," the name 

 referring to the mistaken fancy that oranges were the 

 famous aurea mala of the Hesperides. An additionally 

 curious feature consists in the presence, not infrequently, 

 in the larger forms, of a secondary series of carpels, much 

 smaller than the principal ones, but still in a distinct 



