39° 



ZONES AND REGIONS 



[Pt. Ill, Sect. I 



shores, and whose rapidly growing shoots, frequently several meters long, 

 generally advance nearest to the sea of all vegetation. Fig. 209 shows the 

 typical Pes-caprae formation. In other areas, other plants of a similar 

 habit prevail, so that, for instance, we can distinguish a Canavalia-formation 

 — named from a papilionaceous genus, several species of which are dis- 

 tributed on the eastern Asiatic shore — or a Spinifex-formation, and so 

 forth. Fig. 210 shows how the Pes-caprae formation develops in more 

 sheltered places. The creeping shoots cover the ground with a network 

 that is only here and there interrupted by larger gaps. Some other plants 



FlG. 212. Shrub formation on the sea-shore, close to high-tide mark, near Singapore. In the 

 main Pandanus sp., here and there Scaevola Koenigii and Thespesia populnea. From a photograph 

 by P. Groom. 



have taken root on the soil that has become firm, in particular some 

 grasses, and two shrubby species, Scaevola Koenigii and a Croton, are 

 recognizable. 



In still more sheltered spots, however, on less shifting, coarse or pebbly sand, 

 shrubs become more numerous, and little trees, in the Old World species ot 

 Pandanus, are added (Figs. 211, 212). 



In Eastern Asia in such stations, Pemphis acidula very frequently occurs, a bushy 

 lythraceous shrub with small succulent leaves bearing silvery grey scales ; Clero- 

 dendron inerme, a somewhat thorny shrub, whose long branches covered with 



