LECT. X.] SITUATION OF LEAVES. 533 



of plants proceeding from seeds that have more 

 than one seed-lobe. The seminal leaf (/'. semi- 

 note) is, in fact, a transformation of a seed-lobe 

 to a leaf of a very temporary duration, and which 

 performs the functions of a leaf until the real 

 leaves appear, after which it drops off. 



Although it may be anticipating the remarks 

 we have afterwards to make on the nature and 

 functions of the cotyledon, yet it is proper to state 

 here, that the cotyledon is a nutritive organ, con- 

 taining in its cells a large portion of farinaceous 

 matter, which becomes saccharine during the 

 germination of the seed, and is admirably adapted 

 for the nourishment of the embryon plant. In 

 those seeds, the cotyledons of which rise above 

 the ground when they vegetate, as, for instance, 

 the Lupine, the cotyledons acquire a green colour 

 as soon as they are exposed to the light; and then, 

 besides continuing to supply nutriment to the 

 young plant, the root of which is still incapable of 

 taking up any thing from the soil, perform all the 

 functions of the real leaf. If the seminal leaves 

 be destroyed before the other leaves appear, the 

 plant dies ; and, therefore, as the saccharine qua- 

 lities of the seminal or cotyledon leaves in the 

 Turnip attract a species of small beetle, which 

 does not attack the proper leaves of the plant, whole 

 crops of this useful vegetable are often destroyed. 

 Farmers, indeed, do not consider the crop of tur- 



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