﻿RIVERS 
  AS 
  FACTORS 
  IN 
  ANIMAL 
  DISTRIBUTION. 
  183 
  

  

  giant 
  tree 
  upon 
  a 
  river-bank 
  is 
  carried 
  away 
  by 
  a 
  sudden 
  

   inundation, 
  and 
  floats 
  upright 
  out 
  to 
  sea, 
  supported 
  by 
  the 
  mass 
  

   of 
  earth 
  in 
  the 
  clasp 
  of 
  its 
  widespread 
  roots. 
  When 
  the 
  soil 
  

   melts 
  away 
  the 
  tree 
  is 
  subverted 
  with 
  a 
  crash, 
  the 
  island 
  dis- 
  

   appears, 
  and 
  a 
  naked 
  log 
  drifts 
  too 
  and 
  fro 
  upon 
  the 
  waves."* 
  

   Mr. 
  Hickson 
  may 
  be 
  quoted 
  for 
  Celebes: 
  "During 
  the 
  heavy 
  

   rains 
  of 
  1882 
  the 
  Manado 
  Eiver 
  brought 
  down 
  vast 
  numbers 
  of 
  

   mighty 
  forest 
  trees, 
  and 
  many 
  of 
  these 
  must 
  have 
  drifted 
  out 
  to 
  

   sea 
  with 
  a 
  very 
  considerable 
  crew 
  of 
  Squirrels, 
  Mice, 
  cater- 
  

   pillars, 
  and 
  other 
  animals. 
  "t 
  

  

  The 
  distribution 
  of 
  plants 
  is 
  also 
  largely 
  influenced 
  by 
  the 
  

   action 
  of 
  rivers, 
  and 
  many 
  species 
  are 
  thus 
  dispersed 
  which 
  

   would 
  have 
  scarcely 
  any 
  wide 
  distribution 
  by 
  other 
  means. 
  On 
  

   the 
  banks 
  of 
  rivers 
  and 
  streams, 
  " 
  a 
  portion 
  of 
  the 
  plant- 
  

   fragments 
  brought 
  by 
  floods 
  and 
  stranded 
  on 
  the 
  mud 
  of 
  calm 
  

   inlets 
  undergoes 
  decomposition. 
  A 
  larger 
  portion 
  remains 
  fresh 
  

   and 
  living, 
  sending 
  out 
  roots 
  and 
  vigorous 
  shoots. 
  In 
  the 
  bed 
  of 
  

   the 
  Danube, 
  in 
  addition 
  to 
  the 
  abundant 
  creeping 
  shoots 
  of 
  the 
  

   reeds 
  (Phrag 
  mites), 
  and 
  various 
  sedges, 
  bulrushes 
  (Scirpus, 
  

   Tupha), 
  broken 
  twigs 
  of 
  Salix 
  frag 
  His, 
  bits 
  of 
  root 
  of 
  the 
  sea- 
  

   buckthorn 
  (Hippophce 
  rhamnoides) 
  , 
  and 
  fragments 
  of 
  the 
  rhizomes 
  

   of 
  (JEnanthe 
  phellandrium 
  and 
  Acorus 
  calamus, 
  leafy 
  twigs 
  and 
  

   stolons 
  of 
  various 
  species 
  of 
  pondweed, 
  water-milfoil, 
  and 
  water- 
  

   ranunculus 
  (Potamogeton, 
  Myriophyllum, 
  Ranunculus 
  aquatilis) 
  

   are 
  all 
  distributed 
  in 
  this 
  way. 
  Sometimes 
  these 
  growths 
  settle 
  

   in 
  places 
  where 
  formerly 
  no 
  specimen 
  of 
  the 
  kind 
  had 
  been 
  seen 
  

   for 
  miles, 
  and 
  the 
  fact 
  may 
  be 
  easily 
  confirmed 
  that 
  the 
  distribu- 
  

   tion 
  of 
  their 
  offshoots 
  is 
  actually 
  brought 
  about 
  by 
  flowing 
  water 
  

   in 
  a 
  very 
  short 
  time 
  to 
  great 
  distances 
  and 
  in 
  great 
  abundance."]; 
  

   In 
  the 
  Malay 
  Peninsula, 
  Hodgsonia 
  heteroclita 
  frequents 
  dense 
  

   thickets 
  on 
  river-banks. 
  It 
  bears 
  very 
  large 
  woody 
  gourds, 
  

   covered 
  with 
  a 
  grey 
  pubescence. 
  These 
  gourds 
  drop 
  from 
  the 
  

   plant 
  when 
  ripe, 
  and 
  float 
  in 
  the 
  river. 
  The 
  pubescence 
  prevents 
  

   them 
  from 
  injury 
  by 
  wet, 
  so 
  much 
  so 
  that 
  a 
  gourd 
  may 
  be 
  

   plunged 
  in 
  the 
  water 
  and 
  taken 
  out 
  again 
  dry. 
  The 
  seeds, 
  too, 
  

   are 
  large 
  and 
  woody 
  ; 
  they 
  float 
  in 
  water, 
  and 
  are 
  protected 
  from 
  

  

  :: 
  ' 
  Advent, 
  among 
  the 
  Dyaks 
  of 
  Borneo,' 
  p. 
  185. 
  

  

  f 
  ' 
  A 
  Naturalist 
  in 
  North 
  Celebes,' 
  p. 
  190. 
  

  

  | 
  Kerner 
  and 
  Oliver, 
  ' 
  Nat. 
  Hist. 
  Plants,' 
  vol. 
  ii. 
  p. 
  808. 
  

  

  