256 DECOMPOSITE ORGANS, CHAP. I. 



often such as the term albumen suggests, is by no 

 means always so. In the Grasses it is farinaceous ; 

 in the Umbelliferce it is woody ; in the seed of 

 Coffee-plant it is horny ; and in that of the Date- 

 Colour, palm it is said to be as hard as a stone.* Its colour 

 is generally whitish ? but inBocconia it is yellow ; in 

 Codon it is red ; and in the Missletoe it is green. 

 Lastly, the albumen of most seeds is altogether 

 without odour and without taste ; but in Ginger, 

 Nutmeg, and Pepper, it is sapid and aromatic. 

 Itsde- ARTICLE 2. The Vitellus. The vitellus is an 



organ of a fleshy but firm contexture, situated 

 when present between the albumen and embryo ; to 

 the former of which it is attached only by adhe- 

 sion, but to the latter by incorporation of substance, 

 so as to be inseparable from it except by force. 

 Hence, perhaps, it has been supposed to bear the 

 same relation to the embryo which the yolk of the 

 egg bears to the cicatricle ; as well as to exhibit a 

 character by which it may be always distinguished 

 from the albumen, which is only contiguous to the 

 embryo but not incorporated into it. It had been 

 observed by Malpighi and others of the earlier 

 First phytologists, but not named nor distinctly charac- 

 G*mier. y terized till it was studied and investigated by 

 Gaertner; though even now there are many 

 botanists who do not regard it as constituting a 

 vitellus, but merely as a part of the embryo pecu- 

 liarly organized. And the comparatively small 

 * Smith's Introduction, p. 29 1. 



