380 NOTES OF A BOTANIST 



are (with one notable exception a ) no aquatics and 

 no shore grasses. Compare this with the broad 

 fringe of tall, succulent, amphibious grasses on the 

 shores of the Amazon, or detached and floating down 

 it in the shape of large islands, and of luxuriant 

 aquatics, some fixed by roots, others floating 

 (Victoria, Jussiaea, Pontederia, Frogbits, Azolla, 

 Salvinia, Pistia, etc.), in deep still bays, but especi- 

 ally in lakes and channels communicating with the 

 main river. 



Some of the tributaries of the Rio Negro, how- 

 ever, have plenty of fish, namely, those of more or 

 less turbid water, of which the Rio Branco holds 

 the first rank, and after it come the Marania and 

 Cauaboris, all entering on the left bank. In these 

 rivers many Amazon fish are said to be repeated. 

 About the mouth " of the Rio Branco is the only 

 place in the Rio Negro where the Pirarucii is found 

 -that noble and remarkable fish, so characteristic 

 of the Amazon. With the exception of the Pirarucu, 

 most of the larger fish of the Amazon recur on the 

 Upper Orinoco, above the cataracts ; at least the 

 Indians assert them to be the same, and to unskilled 

 eyes they are undistinguishable. The Valenton 

 or Lablab of the Orinoco, for instance, is surely 

 the same as the large Pirahyba of the Amazon ; 

 the Pavon as the Tucunare ; the Rallado as the 

 Surubim ; the Muruciitu as the Tambaqui ; the 

 Cajaru as the Pira-arara, and so on. 







Many of the fishes of the Rio Negro travel up it 

 to spawn, and especially up some of its tributaries ; 

 Inn the wanderings to and fro of fish in quest of 



That of the Podostemons on granite rocks in the falls and rapids. 



