IvrORI'HOLOGY OF THE FRUIT AND SEED 267 



the seed is said to be winged. These winged seeds must be 

 carefully distinguished from samaroid fruits, such as the Ash, 

 Elm, and Maple {fig. 541), where the wing is an expansion of 

 the pericarp instead of the testa. In like manner, hairy seeds 

 should not be confounded with pappose friiits, such as those of 

 the Compositai, Dipsacese (fig. 294), and Valerianaoese (fig. 293), 

 where the hairy processes belong to the calyx. 



Beneath the testa, in anatropous seeds (figs. 583, E, and 

 577, rap), and the modification of these termed amphitropous, 

 the raphe or vascular cord connecting the hilum with the 

 chalaza is found. Its situation is frequently indicated by a pro- 

 jecting ridge on the surface of the seed, as in the Orange, while 



Fig. 581. 



Fig. .')S2. 



Fig. 581. Marginate or bordered seed of Sandwort (^Armarta). Fi'j. 582. 



Comose oval seed of Asclepias. Ful. 583. Toung anatropous seed of the 



White Water-lily {Nymphtea alba) cut vertically. F. Funiculus. A, A. 

 Gelatinous aril. t. Integuments of the seed. N. Nucellus. il. Raphe. 

 ch. Chalaza. M. Micropyle. s. Embryo-sac. E. Rudimentary embryo. 



at other times it lies in a furrow formed in the substance of 

 the testa, so that the surface of the seed is smooth, and no 

 evidence is afforded externally of its position. 



The testa is also usually marked externally by a scar indi- 

 cating the hilum or point by which it was attached to the funi- 

 culus or placenta. The micropyle, as already noticed, may be 

 also sometimes seen on the surface of the testa, as in the Pea 

 (fig. 577, m) ; but in those cases where no micropyle can be de- 

 tected externally, its position can only be ascertained by dissec- 

 tion, when it wiU be indicated by the termination of the radicle, 

 this being directed, as already alluded to, towards the micropyle. 

 In some seeds, as in the Asparagus, the situation of the micro- 

 pyle is marked by a small hardened point, which separates like 



