STRUCTURE OF SEED. 183 



an aqueous pulp, retained around them by a very 

 delicate membranous net-work ; Lepidium sativum, the 

 common Flax, and several other seeds, exhibit this 

 phenomenon, which must tend to facilitate their ger- 

 mination. 



Among the different examples of the accessory integu- 

 ments of seeds which I have mentioned, the origin of 

 the arillus, as a prolongation of the funiculus, is very 

 evident ; but the origin of the epidermis is much less so ; 

 it may be considered as proceeding also from the funi- 

 culus on account of its position around the seed, and 

 because it is evidently an organ in addition to those 

 which essentially compose the seed. 



CHAPTER IV. 



OF THE STRUCTURE OF THE SEED OF PHANEROGAMOUS 



PLANTS. 



Section I. 



Of the Seed in general. 



A Seed (semen) considered with regard to the flower, 

 is a fecundated ovule ; considered individually, it is a 

 cavity closed on all sides, containing the rudiment of a 

 plant. It is composed of the embryo or germ, which 

 has received the fecundation, and of its different appen- 

 dages, some of which serve as nourishing organs, and 

 the others as protecting integuments. 



