STRUCTURE OF FRUIT. 177 



but during and after flowering, several of them become 

 abortive, so that the capsule frequently has but two 

 cells and two or three seeds. 



Thus, the spiny husk of the Chestnut is an involucrum, 

 that of the Horse-Chestnut a capsule. The brown, 

 shining, round bodies of the Chestnut are achenia, 

 furnished at the base with a large carpal cicatrice; those 

 of the Horse-Chestnut are seeds with a large spermal 

 cicatrice. The bodies enclosed in the brown envelope of 

 the Chestnut are distinct seeds ; those within the brown 

 skin of the Horse-Chestnut are the cotyledons, or por- 

 tions of the seed. Although this example is trivial for 

 botanists, I thought that I ought to mention it in detail 

 for beginners, because, better than all reasoning, it 

 proves the necessity of referring to the period of flower- 

 ing in order to comprehend the structure of fruit. 



Section VII. 



Of the Umbilical Cord and its Expansions. 



We have already said, that the Funiculus or Um- 

 bilical Cord proceeds from the placenta, and supports 

 the seed ; that it is composed, during flowering, of the 

 filament proceeding from the style and bearing the 

 fecundating fluid, and of a fibre coming from the pedicel 

 and carrying the nourishment ; that after this period, 

 the pistillary filament is obliterated, and the funiculus 

 remains formed of the nourishing fibre alone : we may 

 consider it as making part of the pericarp, either on 

 account of its texture analogous to the placenta, or 

 because that, at maturity, it usually happens that it 

 remains adherent to the placenta when the seed is 



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