JZ20 NEW ORGAN IN SEEDS. 



seeds, have enabled me to add a law to carpology, which 

 I conceive to be of such a nature as to admit no ex- 



ception. 



Frnits consist Tliovoughly to understand this law, it is necessary to 

 et f&ur distinct ii , .i i, /• •, i n r ■,-.'. 



parts, recoiiect, that all fruits are composed ot tour very distinct 



parts, each of whish has its own peculiar system of vessels. 

 The first ia the pericarp ; the second, the outer integument 

 of the seed ; the third, the internal membrane ; and the 

 fourth, the embryo. But I conceive, that, to facilitate the 

 study of carpology, it will be sufficient to divide fruits into 

 The last three two parts only ; the first of these being that envelope of 

 ^IrL ,^. ^°!1^'" various forms, and of various substance, which botanists 

 term the pericarp ; and the second, the seed, which is al- 

 ways united by an umbilical cord to a central receptacle, 

 detached or adherent, or to the inside of the pericarp. 

 These two parts, which have been too frequently con-» 

 founded together, may be discriminated in future by inva- 

 Cfearacters by riable characters easily distinguished. A seed must always 

 Biay bi-^d'sUn- ^^ attached to an umbilical cord, longer or shorter, and 

 guished from a always provided with two cicatriculte at its base, one of 

 pericajp. ^hich is the nutrimental umbilicus, the other the micro- 



pyle : but it cannot in any case have a style, since the 

 styles themselves are nothing more than an elongation of the 

 Tbe acorn, placenta, or receptacle. Thus the acorn separated from its 

 chesnu', and cup, the chesnut divested of its bristly coat, the nut of the 

 Junibiuiii,noi nelumbium taken out of its receptacle, cannot be seeds 

 seeds. properly so called, since their coats are terminated by 



styles. It is undoubtedly for want of knowing this law, 

 that Gsertner, after having described the acorn and chesnut 

 as pericarps, describes the nut of the nelumbium as a sim- 

 ple seed*. 

 R( capitulation. On considering what has been saia in this paper, it ap- 

 pears, that the micropyle is constantly placed near the um- 

 bilicus at the time of fecundation ; and that, if it afterward 

 recede from it, this is owing to the dilatation of the seed : 



Theniicropyle * The mycropyle maj serve likewise to distinguish the seed from tho 

 <iistiniuisrhes a a)il. The latter, as Mr. Richard has very justly observed, being onl/ 

 seed from an 3^ expansion of tbe umbilical cord, which covers the seed wholly or in 

 *'^ ' part, cannot have the micropyle, the orifice of which is always in the 



proper cuat of the seed. 



that 



