COMPARATIVE VIEW. 169 



advanced, but yet in a state of considerable development, 

 indicated either by the entire want or scanty remains of 

 albumen : the only exception to this being Leea, in which 

 the embryo is many times exceeded in size by the albumen. 



In the Monocotyledonous plants, on the other hand, con- 

 sisting of Graminese, Cyperacese, Gloriosa, Plagellaria and 

 Pistia, the embryo bears a very small proportion to the 

 mass of the seed, which is formed of albumen, generally 

 farinaceous. But it may here be observed that the existence 

 of a copious albumen in Monocotyledones does not equally 

 imply an inferior degree of vitality in the embryo, but [482 

 may be considered as the natural structure of that primary 

 division ; seeds without albumen occurring only in certain 

 genera of the paradoxical Aroidese, and in some other 

 Monocotyledonous orders which are chiefly aquatic. 



5th. Doubts may be entertained of the identity of particu- 

 lar species. On this subject I may observe, that for what- 

 ever errors may be detected in these lists, I must be 

 considered as solely responsible ; the insertion of every 

 plant contained in them being founded on a comparison of 

 specimens from the various regions of which their existence 

 in the particular lists implies them to be natives. The only 

 exception to this being Lipocarpha argentea, of which I 

 have not seen American specimens ; as a native of that 

 continent therefore it rests on the very sufficient authority 

 of Baron Humboldt and M. Kunth. 



In my remarks on the natural orders, I have already 

 suggested doubts with respect to certain species included 

 in the lists, and shall here add a few observations on such 

 of the others as seem to require it. 



Jcrosticfium aureum, L. was compared, and judged to 

 agree, with American specimens; and I have therefore 

 placed it in the 2nd list, without, however, meaning to 

 decide whether those plants originally combined with A. 

 aureum, and now separated from it, should be regarded as 

 species or varieties. 



Fuirena umbellata, L. fil. from Congo, has its umbels 

 somewhat less divided than either the American plant or 

 that from the continent of India ; but from specimens 



