FLOEA OF AMAZONIA. 



105 



whicli ramify amid the thousands of archipelagoes strewn over the Amazons. 

 Here the pUmts overhanging the stream present an infinite variety of vegetable 

 life, feathery or fan-shaped foliage, pendent clusters of bloom, gorgeous festoons 

 of flowery creepers. 



Viewed as a whole, the Amazonian flora is quite distinct from that of Brazil 

 proper. Both doubtless possess many forms in common ; but the contrasts are 

 numerous, and the Para region resembles Cayenne in its flora and fauna far more 

 closely than it does South Brazil. This remarkable fact seems to confirm the 

 opinion of those geologists who hold that the Amazonian waters were formerly 

 barred by a transverse ridge from access to the Atlantic through the present 

 estuary. The species originating on the Guiana uplands might thus have been 

 easily propagated southwards across Mara jo and the other islands to South 



Fig. 36. — Amazonian Selta. 

 Scale 1 : 40,000,000. 



West oF G 



Savannas. 



Forests. 



Catingas. 



- 930 Miles. 



Amazonia. With these were intermingled some Andean forms descending from 

 the upper to the lower reaches after the rupture of the transverse dyke. 



An endless variety of local forms corresponds with the varying character of the 

 soil, in one place alluvial or rocky, in another saudy or clayey, dry or marshy. 

 The more recent riverside igapos, 14 or 15 feet above low-water mark, in many 

 places occupying lacustrine depressions many hundred square miles in extent, are 

 overgrown with tall grasses, willows, or trumpet-trees {cecropias). The zone of 

 older igapos is recognised at a distance by other forms, including the rubber-tree 

 {siphonia elastica). Higher up the belt of clays and alluvial tracts, flooded only 

 during the inundations, are indicated by thickets of various palms and numerous 

 other species. Then follows the firm ground, the old argillaceous bed of the inland 

 seas, where flourish most of those large trees whose wood exceeds in beauty and 

 hardness that of the finest European forms. 



Although nowhere rivalling the Australian or Californian giants, some of the 



