208 FRUIT. 



it more resembles the cotyledons, but as it remains en- 

 closed in the seed during germination it is regarded as 

 a vitellus. 



" The hypogean or sub-terrestrial cotyledons, are not 

 to be passed over unnoticed ; for although on account 

 of their regular fo.m, and the radicle being always 

 placed without the lobes, and not covered by their 

 substance, they neither can, nor ought to be separated 

 from the rest of the true cotyledons ; yet on account 

 of their incapacity for germinating and the coalition oi 

 iheir lobes into one body, as in the Horse Chesnut, they 

 differ so very little from the vitellus, that there is the 

 closest bond of affinity between these parts ; and in 

 general, nature, in producing these parts of the seeds, 

 seems to proceed from the very simple texture of the 

 albumen, insensibly to the more organic structure of 

 the vitellus, and from this to the more perfect fabric of 

 the cotyledons.'* 



In the Grasses, this organ assumes a different form ; 

 and appears like a mere scale, to which the embryo is 

 attached on one side, and the albumen on the other. 



The Cotyledons, are that portion of the seed which 

 encloses the embryo, and during germination, appear 

 in the form of leaves above the surface of the ground, 

 Fig. 1 10. Each seed is usually furnished with two 

 cotyledons, but in the Hemlock, Pinus Canadensis, there 

 are three, and in other species of Pine they are still 

 more numerous. In some cases the seed is said to 

 contain but one cotyledon, and the Grasses and Lilies 

 are referred to as examples ; in others it is said to be 

 without lobes, and the Mosses, and other imperfect 

 plants are of the number. On this subject, however, 



* Gartner. 



