50 ■ On the Affinities of Ceratophyllacea. 



rather than the perioarpic direction of the embryo should be 

 particularly indicated ; since the former affords characters of 

 the highest rank, from which the latter may be inferred when- 

 considered in connexion with the direction of the seed. It is 

 also desirable that the classification and nomenclature of ovules 

 proposed by Mirbel* should be extended to seeds, and gene- 

 rally employed in systematic descriptions, which would thus be 

 rendered much more simple and perspicuous. Thus, if we 

 use the expression, seed anatropous, it is understood that the 

 micropyle, and consequently the radicle, is situated in the im- 

 mediate vicinity of the hilum, and that the chalaza, or organic 

 base of the seed, occupies (if the embryo be straight, or nearly 

 so,) the portion most remote from the hilum, with which it is 

 connected by means of a prolongation of the funiculus, called 

 the raphe. t 



* Ann. Sciences Naturelles, vol. 17. 



f An instance of the separation of the raphe from the te9ta, in one of 

 the two seeds of the fruit of Seringia platyphylla, is represented by M. 

 Gay in the seventh volume of the Mem. du Museum, t. 17. 



