MANUAL OF NATURAL HISTORY. 515 



cells, when fertile, perforated opposite the 

 seat of the embryo, and, when abortive, indi- 

 cated by coecal foramina ; albumen cartala- 

 ginous or amygdaloid, oleaginous. Among 

 these are the Gocos nucifera, or Coco-nut 

 palm, species of Elais yielding Palm-oil, 

 and Phytelephas macrocarpa, the source of 

 Vegetable Ivory. 



III. ORDER— Arals (Arales). 



Petaloidal, or naked-flowered ; spadix simple, 

 naked; embryo in the axis of mealy or fleshy 

 albumen. 



1. Family. — Screw-pines (Pandanacese). Trees or 



bushes, often sending down aerial roots ; 

 leaves imbricated, amplexicaul, often spiny- 

 edged, or pinnate or fan-shaped ; floral leaves 

 smaller ; flowers often polygamous, naked 

 or scaly, covering the whole of the spadix ; 

 stamens numerous ; filaments with single an- 

 thers, which are 2-4-celled ; ovaries in par- 

 cels, 1 -celled; ovules solitary or numerous; 

 stigmas sessile ; fruit fibrous-drupes collected 

 into parcels, or baccate and many-seeded; 

 seeds loose ; embryo minute, solid. Tropical 

 plants. 



2. Family. — Arads (Aracese). Herbaceous, with a 



fleshy corm, or shrubs ; leaves sheathing ; 

 spadix generally spathaceous ; flowers naked, 

 on the surface of a spadix ; stamens definite 



