38G 



SIR J. LT7BB0GK: — PUYTOTJIOLOOICA'L OBSERTATTOXS. 



They arc bipartite, each primary division narrowing to a 

 cuneate base, and being again deeply divided, so as to make m 



all four ultimate, linear, oblong, obtuse, entire segments. 



la 



this case the endocarp is tliickened, bony, and divided at the base 

 into four cells (fig. 117,cc cc) by the tliickening and consequent 

 intrusion of the dorsal and ventral walls. 



The seed (fig. 118) is conical above, deeply 4-lobed below 

 (fig. 118, nil), one lobe (7) passing into each of these cells (c). 

 The embryo again follows suit, and each cotyledon sends a lobe 

 into each of the four cells, thus assuming the ])eculiar form 

 characteristic of the species. 



Fig. 117. 



Fig. 118. 



772. 



J^terocarya caiicadca, ' 



Fig. 117. Transverse section of nut, X H. 

 Fig. 118. Transverse section of seed, X 6 



In Fschscholtzia (fig. 40) the cotyledons are deeply bifid, re- 

 sembling a hay-fork -with two long prongs. In this case -vvefind 

 no such peculiarity of the fruit or seed to account for the pecu- 

 liarity. My first idea was that such cases might possibly be due 

 to some difference in the perispcrm, as occurs in certain Unibellifers, 



JDclpliinium, &c., and which might have permitted growth more 

 readily in certain directions than in others. Thin sections, how- 

 ever, i>howed no such diff'erences. IMoreover, Sclnzopctalon 

 WaUi-eri (one of the Crucifcrje) (figs. 120-123) has the col}ledons 

 as deejdy divided as in Eschsclwlizia ; and as there is no perispenn, 

 but the embryo occupies the whole seed, within which the long 

 lobes of the cotyledons wind about more or less irregularly, the 

 division cannot be due to differences in the perisperm. There are, 

 moreover, other species, such as the Sycamore (fig. 52) and llop, 

 where the cotyledons are also narrow, winding, and occupy the 



