104 



ON SEEDLINGS 



in Oxymitra patens they are globular with numerous blunt 

 processes; in 0. Grayana they have two, in other species 

 four wings, while others again are round and smooth. 



Cotyledons. The seedlings of Anona are strong and vigorous 

 but present a singular anomaly, inasmuch as the cotyledons 

 are in some species torn from the 

 axis during germination. The seeds of 

 A. laurifolia split longitudinally, the 

 strong radicle strikes straight down- 

 wards fixing the seedling firmly in the 

 soil, and the hypocotyl forms an ascend- 

 ing or elongating loop. The large seed 

 remains underground, while the hypo- 

 cotyl at length pulls out the plumule, 

 and straightens, leaving the cotyledons 

 behind. If a seed is cut open at this 

 point the cotyledons are seen to be 

 oblong or oval, obtuse, petiolate, almost 

 equalling the length and breadth of 

 the seed, and much undulated or 

 wrinkled in order to accommodate 

 themselves to the inequalities of the 

 much ruminated endosperm. They 

 exhibit an ascending, incurved, feather- 

 nerved venation very similar to that 

 of the leaves, and at this stage are 

 surrounded or included between two 

 equal halves of the endosperm with a 

 small quantity of the same between 

 them. A. Cherimolia behaves in ex- 

 actly the same way, and the cotyledons 

 are invariably torn from the axis and 

 left in the subterranean seed. 



A. palustris is an exception to the 

 other species examined, inasmuch as 

 the cotyledons become aerial. They are oval, or oblong- 

 elliptic, obtuse, petiolate, foliaceous, with a penninerved, in- 

 curved venation, and in every respect similar to that of a true 

 leaf with the exception that the leaves are acuminate. 



Half of seed with 

 cotyledon. 



PIG. 139. Anona, ? lauri- 

 folia. Nat. size. 



