JUGLANDE^E 



In a transverse section of the fruit made below the base of the 

 ovary, the four cavities are seen to be filled with the twisted or 

 folded lobes of the cotyledons. 



A longitudinal, but slightly oblique, section through the fruit 

 was made on the 12th of October. Owing to the cotyledons being 

 much folded and twisted, a clear idea of their arrangement can 

 scarcely be obtained in longitudinal section. The radicle is seen at 

 the apex of the seed which is orthotropous. At the base of the 

 cavities formed by the absorption of cortex, the tips of the cotyledon- 

 ary lobes in some instances appear to be folded transversely. A 

 mass of cortex occupies the apex of the fruit. By this date it had 

 not been fully matured and had been damaged by frost ; that is, the 

 exterior parts such as the rind and wings. 



In a transverse section of the same date the cotyledonary lobes 

 are seen to be variously folded in the same fruit. 



Masses of cortex occur in various parts of the fruit, embedded 

 in the more solid and sclerenchymatous endocarp. They are doubt- 

 less intended to lighten the fruit, and aid in its dissemination by 

 means of the wind. The wings formed by the adnate and accrescent 

 bracteoles, and the very thin rind or exocarp of Pterocarya, all 

 point to the natural means of dispersing the frui-t in this genus. 



Seedling (fig. 662). 



Hypocotyl erect, terete, brownish and glabrous in the lower part, 

 greenish upwards and thinly pubescent, 

 about 3 cm. above the soil. 



Cotyledons bipartite, with the pri- 

 mary divisions narrowing to a cuneate 

 base, and again deeply bipartite, making 

 in all four linear-oblong, obtuse, entire, 

 diverging and recurved segments, five- 

 nerved from the base of the lamina, 

 glabrous, dull opaque-green above, paler 

 beneath ; midrib slender, short, ending 

 at the base of the middle fissure of the 

 lamina ; middle nerve on each side of 

 the midrib strong, running along the 

 middle of the primary divisions of the 

 cotyledons and ending with a slender 

 point at the base of their fissure, at the 

 same time giving off a strong lateral nerve on each side a little 

 below the apex, which runs along the middle of the ultimate 



FIG. 662. 



Pterocarya caucasica. 

 Nat. size. 



