THE FRUIT AOT) SEED. 117 



lique, as seen in Fig. 253. In this case the embryo 

 is said to be heterotropal. Fig. 252 represents the 

 seed which is shown in section in Fig. 253. 



If the seed be inverted, or antitropous (Fig. 254), 

 the embryo will be erect, as shown in Fig. 255. Here 

 the embryo is said to be orthotropaL 



FIG. 254. FIG. 255. 



Micropyle. 



In Fig. 256, which represents a seed curved upon 

 itself so as to bring the orifice next the hilum, or 

 point of attachment (campylotropous seed), you may 

 find the embryo presenting the appearance shown in 

 Fig. 257. 



FIG. 256. FIG. 257. 



Hilum. :^f v Micropyle. 



When the embryo is in the centre of the albumen 

 (Fig. 255), it is said to be axial; and when not in the 

 centre, it is said to be excentric. 



Among the various modes of folding to which the 

 embryo is subject, there are two which have been 

 specially noticed and named, because they occur so 

 uniformly in certain groups of plants. They are 

 cotyledons accumbent ; that is, with the radicle folded 

 against their edges ; and cotyledons incumbent, having 

 the radicle folded against the back of one of them. 



