from the usual Structure of Seeds. " 149 



ciently evident; a greater than ordinary evolution of the em- 

 bryo being necessary to ensure its vegetation in the unfavourable 

 circumstances in wliich it is unavoidably placed. , 



But an analogous structure exists in other plants, where the 

 final cause is less apparent, as in certain species of Eugenia, iu 

 Avhich the integument of the seed is coujpletely absorbed l)efore 

 its separation from the parent plant, and while the pericarpiuni 

 remains entire. , 



An economy no less remarkable than that of the Mangroves, 

 but of a nature diametrically opposite, takes place in the bulb- 

 like seeds of certain liliaceous plants, especially of Poncralium, 

 Crimtin and Amaryllis; in some of whose species the seed separates 

 from the plant, and even from the pericarpium, before the embryo 

 becomes visible, 'i his observation respecting some of these seeds 

 was, 1 believe, first made by Mr. Salisbury; and in such as I have 

 niyselt examined, I lia\e found the fact connected with one no 

 less interesting, namely, an unusual vascularity in the fleshy sub- 

 stance. 



I have in another place*, in speaking of this substance, which 

 constitutes the mass of the seed, and in a central cavity of which 

 the future embryo is formed, stated it to be destitute of vessels, 

 and entirely composed of ciliular texture. But on a more careful 

 inspection, of those seeds at least iu wliich the separation precedes 

 the visible formation of the embryo, I now find very distinct spi- 

 ral vessels : — these enter at the umbilicus, ramify in a regular man- 

 ner in the substance of the fleshy mass, and appear to have a cer- 

 tain relation to the central cavity where the embryo is afterwards 

 formed, and wliich, filled with a glairy fluid, is distinctly visible 

 before the separation of the seed. It is a curious consequence of 

 this tardy evolution of the embryo, which in some cases does not 



* Prodr. Flor. Nov. Holland, p. 297. 



become 



