SECT. I. ORGANOGRAPHY AND GLOSSOLOGY. 



113 



remarks, we may add the following: The embryo 

 may be either straight or curved; placed in the centre of 

 the albumen, where this substance exists in a separate 

 form, or else laterally disposed with respect to it. The 

 parts of which it is composed are, 1. The " radicle," 

 which is the conical extremity, afterwards developed 

 into a root; and, 2. The " plumule," consisting of the 

 " cotyledon or cotyledons," and the " gemmule," or 

 first leaf-bud, which is afterwards evolved in the form 

 of stem and leaves. 



The position of the embryo is determined by the 

 direction of its radicle, the point of which is constantly 

 turned towards the " foramen," a small hole pierced 

 through the outer coat of the seed, and of which we 

 shall speak more particularly hereafter. Now, the posi- 

 tion of the foramen varies with respect to the hilum, 

 and may be either on the opposite side, or placed 

 near it, on the same side of the seed. The radicle will, 

 consequently, either point from or towards the hilum, 

 and the embryo become " inverse" (fig. 126. a) or 



" erect" (6) accordingly; or the embryo may lie " trans- 

 verse" (c), when the apex is on one side of the seed, and 

 the radicle cannot be said to point either towards or 

 from the hilum. Some authors, however, make the 

 direction of the embryo to depend also on the position 

 of the seed itself, which may be either erect or pendent 

 within the pericarp ; but this is a circumstance which 

 can merely modify the direction of the embryo with 

 respect to the pericarp, and not with respect to its po- 

 sition in the seed. 



(112.) Cotyledons. In many plants, the cotyledons 

 have comparatively little resemblance to leaves, but in 



