f>f> QV THK COTYLEDONS. 



These are called the Cotyledons, f. 4. Between them 

 is seiited the Embryo or germ of the planr, called by 

 Limiseiis Corculum or little heart, in allusion to the heart 

 of ihe walnut. Mr. Knight denominates it the germen, 

 bill that term is appropriated to a very different part, 

 the rudiment of the fruit. The expanding E.nbryo, re- 

 sembling a little feather, has been for that reason named 

 b} Linnaeus Pliimula ; it soon becomes a tuft of young 

 leaves, widi which the young srem, if there be any, as- 

 cends. Till the leaves unfold, and sometimes after, the 

 cotyledons, assuming their green colour, perform their 

 functions ; then the latter generally wither. This may 

 be seen in the Radish, Lupine, Garden Bean, and vari- 

 ous umbelliferous plants, in all which the expanded coty- 

 ledons are remarkably different from the true leaves. 

 Such is the general course of vegetation in plants fur- 

 nished with two cotyledons, or dicotyledones ; but I 

 have already mentioned a very distinct tribe called mo- 

 nocotyledones ; see p. 60. These are the Grass and 

 Corn tribCj Palms, the beautiful Orchis family, and 

 many others. In these the body of the seed does not 

 ascend out of the ground, and they are rather to be con- 

 sidered as having no cotyledon at all. See Mr. Salis- 

 bury's pajjer in the Transactions of the Linnean Socie- 

 ty, V. 7, on the germination of the Orchis tribe. We 

 reserve more particular remarks on this subject till we 

 examine the structure of seeds. 



Some plants are reckoned by Linnscus to have many 

 cotyledons, as the Fir and Cypress. But the germina- 

 tion of these differs in no respect from that of the gene- 

 rality of dicotyledones. Mi. Lambeit, in his splendid 



