110 



DESCRIPTIVE BOTANY. 



adheres to the pulpy pericarp ; but in the grape 

 (fig. 120. ft), the calyx is free, and forms no part of the 

 fruit; the carpels are complete, and the placenta central. 



11. Pomum. Several membranous, or bony carpels, 

 are embedded in a fleshy 



mass, which is the swollen 

 calyx. Apples (fig. IOC.), 

 medlars (fig. 121.), quinces, 

 &c., are examples. 



12. Samara. The peri- 

 carp is here extended into a 

 flat wing-like appendage, as 

 in the sycamore (fig. L22.) 

 and ash ; the fruit of which 



trees is commonly termed a " key." 



13. Siliqtta. This is the name given to the bi- 

 locular and bivalvular seed- 

 vessels of the Cruciferje. 



The seeds are attached to ggZ Ml^c 

 lateral placenta?; the dissepi- 

 ment is formed by a thin 

 membrane, which is appa- 

 rently a prolongation of the 

 inner skin (endocarjf) of the two carpels (fig. 123.). 



(109.) Seed. It would be impossible to obtain a 

 just notion of the seed, without first tracing the ovule 

 through the several alterations which it undergoes, after 

 it has been subjected to the fertilising influence of the 

 pollen ; but, as such details are more especially con- 



