in several distinct races of vascular Plants. 273 
2. The real cotyledons contain that substance which has 
(not indeed very appropriately) been termed Albumen by 
Gsertner, which is destined to nourish and promote the evolu- 
tion of the infant progeny of the species. Whereas, the suppo- 
sed monocotyledon contains none of this alimentary farina- 
ceous substance, being the mere envelope of one of the germs 
of the seed ; in fact, an abortive sheathing leafet, common to the 
seminal and cauline germs of various kindred tribes. 
3. Supposing the true cotyledons of the CrucjEer*, for ex- 
ample, were cut off from the remaining parts of the embryo, 
there would still remain all of the organs which possess any just 
analogy with those of the embryo of the supposed monocoty- 
iedonous tribes. 
4. Whilst every one admits the existence and definite posi- 
tion of the true cotyledons, almost every author differs as to 
the position of the supposed monocotyledon. M. Jussieu ap- 
plies the term monocotyledon to the scutula or scale, at the base 
of the seeds of the Gramineae. Gsertner applies this term to the 
body of the embryo ; whilst Mirbel * and Cassini, in a late num- 
ber of the Journal de Physique, affix the term monocotyledon to 
the first enveloping leafet of the germ ; but, as I have already 
shown ■)*, this would entitle every one of the first sheaths of the 
several germs of the seed to the same designation, which would 
be ridiculous. The opinion of Linnaeus was, that the farinaceous 
perisperm was the monocotyledon, — a substance totally distinct 
from the embryo, in the whole of the supposed monocotyledonous 
tribes. 
5. The existence of the monocotyledon being then imagina- 
ry, the term monocotyledonoIjs is false, leads to error, and 
ought to be laid aside. The term ENDOGENi:, proposed by 
Decandolle, seems at first more appropriate ; yet even this term 
must be limited in its application. The great and very natural 
Family of umbelliFer.e possess real cotyledons, but are not 
eocogcna. I have shown that the Filices are endogen^e, but Still 
this singular race are totally distinct from all the rest of this 
proposed division. 
* Physiologie vegetale, &c. 
f Observations on the Germination of the GraminOae, Memoirs of the Werner 
rian Natural History Society , vol i. 
VOL. IX, NO. 18. OCT. 1823. 
s 
