FUNCTIONS OF PANDANE^. 379' 



assigned in the Economy of nature, to this family of sea-side 

 plants, viz. to take the first possession of new-formed land, 

 just emerging from the water, we see in the disposition of 

 light buoyant fibres within the interior of these fruits, an 

 arrangement peculiarly adapted to the office of vegetable 

 colonization.* The sea -side locality of the Pandaneae, causes 

 many of their fruits to fall into the water, wherein they are 

 drifted by the winds and waves, until they find a resting 

 place upon some distant shore. A single drupe of Panda- 

 nus, thus charged with seeds, transports the elements of 

 vegetation to the rising volcanic and coral islands of the 

 modern Pacific. The seed thus stranded upon new-formed 

 land, produces a plant which has pecuhar provision for its 

 support on a surface destitute of soil, by long and large aerial 

 roots protruded above the ground around the lower part of 

 its trunk. (See PI. 68. Fig. 1.) These roots on reaching 

 the ground are calculated to prop up the plant as buttresses 

 surrounding the basis of the stem, so that it can maintain its 

 erect position, and flourish in barren sand on newly elevated 

 reefs, where httle soil has yet accumulated. 



from two to fourteen in number, and many of them are abortive, (Fig. 13.) 

 The seeds within each drupe of Pandanus are enclosed in a hard nut, of which 

 sections are given at P'igs. ]4, 15. These nuts are wanting in the Podo- 

 carya, whose seeds are smaller than those of Pandancre, and not collected 

 into drupes, but dispersed uniformly in single cells over the entire circum- 

 ference of the fruit. (See PI. 63, Figs. 3, S, 10.) The collection of the seeds 

 into drupes surrounded by a hard nut, in the fruit of Pandanus, forms the 

 essential difference between this genus, and our new genus, Podocarya. 



In the fruit of Pandanus, PI. 63, Figs. 11, 16, 17, the summit of each cell 

 is covered with a hard cap or tubercle, irregularly hexagonal, and crowned 

 at its apex with the remains of a withered stigma. We have a similar 

 covering of hexagonal tubercles over the cells of Podocarya (PI. C3, Figs. 

 5, a. 8, a. 10, a.) The remains of a stigma appear also in the centre of 

 these hexagons above the apex of each seed. (Figs. 8, a. 10, a.) 



* There is a similar provision for transporting to distant regions of the 

 ocean, the seeds of the other family of sea-side plants which accompanies 

 the Pandanus, in the buoyant mass of fibrous covering that surrounds the 

 fruit of the Cocoa-nut^ 



