STRUCTURE OF SEED. 193 



name of Amnios is given. This liquid is, or may be, 

 transmitted into the cavity of the seed by the umbilical 

 cord, or more probably is secreted by the endopleura. 



As soon as fecundation has taken place, the embryo, 

 which swims in the amnios, begins to be developed ; it 

 occupies more space, and the amnios consequently di- 

 minishes; it is probably absorbed by the embryo, to 

 which it may serve for nourishment, or it may be re- 

 absorbed by the neighbouring organs : whatever becomes 

 of it, it happens after a certain time, that, in some 

 plants, the whole of it disappears, and the embryo alone 

 occupies the cavity ; in others, the more fluid part of it 

 alone disappears, but its solid particles are deposited, 

 and solidify into a particular body, to which many 

 different names have been given, but I prefer that of 

 Albumen, both because it makes allusion to the albumen 

 of eggs, and because the name is applicable to this 

 substance in its being of a white colour in all seeds. 



The albumen is less an organ, properly so called, than 

 the residue of one, or a deposit formed in cellular 

 tissue ; it does not present, at least at the maturity of 

 the seed, any organic connexions either with the endo- 

 pleura or embryo ; we do not perceive in it any vascular 

 organization, but only a mass composed of cellular 

 tissue, and not adhering to any of the neighbouring 

 organs : if this be not the case perhaps in some of the 

 Coniferae and Cycadeae, where there is a slight adhesion 

 between it and the radicle. What has often induced 

 persons to speak of the albumen adhering to the spermo- 

 derm, is, that several naturalists have described as 

 albumen, the endopleura when it is thick and fleshy : it 

 is this that happens in those Leguminosae in which the 

 existence of albumen has been admitted. The seed in 

 which the nature of this body can be followed with the 

 greatest facility is the immense one of the Cocoa-Nut 



VOL. II. o 



