XYCTAGIXILE 401 



the latter may be wholly amalgamated with the pericarp. 

 Endosperm is copious, farinaceous, fleshy or mucous, or scanty, 

 and sometimes almost wanting. The embryo is sometimes 

 straight with broad, foliaceous, conduplicate cotyledons sur- 

 rounding or enclosing the endosperm, with a short inferior 

 radicle ; in other cases it is doubled upon itself with broad, 

 foliaceous, incumbent and convolute cotyledons wrapped round 

 the endosperm ; or the cotyledons are narrow and closely 

 applied to the latter. When the embryo is doubled upon 

 itself, the radicle is long, and external to the endosperm, with 

 its tip close to the inferior basal micropyle. 



An unusual character occurs in Cryptocarpus which has 

 an annular embryo ; and in Abronia one of the cotyledons is 

 small and almost aborted. 



Two different types of embryo occur amongst the seeds 

 observed. The cotyledons are always unequal, but in some 

 cases one is nearly aborted. The anthocarp of Mirabilis longi- 

 flora is obovoid, closed by constriction above the true fruit, 

 hardened or crustaceous and sculptured on the outer sur- 

 face. The pericarp is thin and membranous as is the testa 

 which adheres to it. The embryo is doubled upon itself 

 with unequal, concave cotyledons occupying the periphery 

 of the seed and enclosing the farinaceous endosperm. The 

 radicle is long, terete, stout and occupies the other side 

 of the seed, and together with the outer cotyledon deter- 

 mines the smaller size of the inner cotyledon by restricting 

 its growth. The anthocarp of Oxybaphus nyctagineus is 

 oblong, obtusely five-angled, hairy and closely invests the 

 fruit, and that again the seed which conforms to the in- 

 terior. The outer cotyledon is very broad, almost oblate 

 and surrounds the endosperm with its edges closely abutting 

 against the radicle. The inner and smaller cotyledon also 

 comes close up against the radicle with its edges. In other 

 respects this species resembles Mirabilis longiflora. The 

 radicle in both cases is curved at its base and longer than the 

 cotyledons. 



The second type is represented by Abronia umbellata 

 (fig. 602, B). The anthocarp is strongly five- winged with the 

 wings broadest at the upper end. The ovary and seed are 



n. D D 



