﻿230 
  Scientific 
  Intelligence. 
  

  

  III. 
  Botany. 
  

  

  1. 
  JBeitrage 
  zur 
  Physiologie 
  der 
  Wurzeln 
  y 
  by 
  Aug. 
  Rimbach. 
  

   (Berichte 
  d. 
  Deutsch. 
  Botan. 
  Gesellsch., 
  vol. 
  xvii, 
  Berlin, 
  1899, 
  

   p. 
  18.) 
  — 
  The 
  morphology 
  and 
  physiology 
  of 
  the 
  root 
  is 
  a 
  sub- 
  

   ject 
  that 
  has 
  been 
  studied 
  comparatively 
  little 
  heretofore, 
  and 
  

   the 
  author 
  is 
  one 
  of 
  the 
  few 
  botanists 
  who 
  have 
  called 
  attention 
  

   to 
  the 
  fact, 
  that 
  roots 
  in 
  many 
  cases 
  exhibit 
  almost 
  as 
  many 
  and 
  

   as 
  significant 
  modifications 
  as 
  exist 
  in 
  stems 
  and 
  leaves. 
  Roots 
  

   are 
  often 
  looked 
  upon 
  as 
  simply 
  "nutritive," 
  and 
  are 
  generally 
  

   passed 
  by 
  in 
  morphological 
  and 
  anatomical 
  studies; 
  in 
  systematic 
  

   works 
  they 
  as 
  well 
  as 
  rhizomes 
  are 
  as 
  a 
  rule 
  neglected. 
  It 
  

   is, 
  therefore, 
  the 
  more 
  interesting 
  to 
  learn 
  something 
  about 
  

   these 
  organs, 
  which 
  the 
  author 
  has 
  studied 
  very 
  carefully 
  for 
  

   several 
  years 
  in 
  the 
  laboratory 
  and 
  in 
  the 
  field. 
  He 
  proposes 
  

   four 
  types 
  : 
  nutritive-, 
  attachment-, 
  contractile- 
  and 
  storage- 
  

   roots. 
  Roots 
  of 
  the 
  first 
  type 
  are 
  characterized 
  by 
  possessing 
  no 
  

   very 
  pronounced 
  power 
  of 
  resistance, 
  since 
  they 
  have 
  no 
  stertids, 
  

   nor 
  are 
  they 
  contractile 
  nor 
  especially 
  adapted 
  to 
  store 
  nutritive 
  

   matters. 
  Their 
  only 
  function 
  is 
  evidently 
  to 
  absorb 
  and 
  conduct 
  

   nutrition. 
  Certain 
  plants 
  possess 
  no 
  other 
  roots 
  than 
  these, 
  e. 
  g. 
  : 
  

   Dentaria, 
  Corydalis 
  cava, 
  Paris, 
  Tidipa 
  and 
  others. 
  Such 
  roots 
  

   are 
  generally 
  more 
  slender 
  than 
  others. 
  The 
  cortical 
  parenchyma 
  

   is 
  very 
  poorly 
  developed 
  and 
  does 
  not 
  persist 
  for 
  any 
  consider- 
  

   able 
  length 
  of 
  time. 
  Furthermore, 
  they 
  are 
  very 
  plastic, 
  being 
  

   able 
  to 
  change 
  their 
  direction 
  of 
  growth 
  in 
  accordance 
  with 
  the 
  

   local 
  surroundings, 
  — 
  the 
  conditions 
  of 
  the 
  soil, 
  for 
  instance. 
  Not 
  

   uncommonly, 
  however, 
  this 
  same 
  structure 
  may 
  be 
  recognized 
  

   near 
  the 
  apex 
  and 
  in 
  the 
  minor 
  ramifications 
  of 
  roots 
  of 
  the 
  other 
  

   categories. 
  As 
  a 
  second 
  category 
  are 
  to 
  be 
  distinguished 
  such 
  

   forms 
  of 
  roots 
  as 
  do 
  not 
  store 
  nutritive 
  matters 
  and 
  are 
  not 
  

   contractile, 
  and 
  in 
  which 
  the 
  power 
  of 
  absorption 
  is 
  so 
  small 
  that 
  

   their 
  only, 
  or 
  at 
  least 
  most 
  important, 
  function 
  seems 
  to 
  consist 
  in 
  

   attaching 
  the 
  plant 
  to 
  the 
  substratum. 
  These 
  roots 
  are 
  named 
  

   i( 
  attachment-roots." 
  They 
  are 
  rare 
  and 
  may 
  be 
  found, 
  for 
  

   instance, 
  in 
  the 
  epiphytic 
  Bromeliacem. 
  Considered 
  from 
  an 
  

   anatomical 
  point 
  of 
  view, 
  these 
  roots 
  are 
  very 
  rich 
  in 
  stereome, 
  

   while 
  the 
  cortical 
  parenchyma 
  is 
  relatively 
  poorly 
  developed 
  and 
  

   frequently 
  collapses. 
  There 
  are, 
  however, 
  certain 
  roots 
  which 
  

   besides 
  a 
  purely 
  mechanical 
  function, 
  also 
  possess 
  power 
  of 
  

   absorption. 
  Such 
  modifications 
  are 
  especially 
  characteristic 
  of 
  

   JPalmce, 
  Gramineoe, 
  Cyclanthacem 
  and 
  Aracece, 
  epiphytic 
  as 
  well 
  

   as 
  terrestrial. 
  The 
  contractile 
  roots 
  constitute 
  the 
  third 
  category. 
  

   Their 
  main 
  function 
  lies 
  in 
  their 
  power 
  of 
  contracting 
  and 
  thus 
  

   drawing 
  the 
  shoot 
  deeper 
  and 
  deeper 
  down 
  into 
  the 
  ground. 
  

   These 
  roots 
  have 
  very 
  little 
  or 
  no 
  sterome, 
  but 
  possess 
  an 
  enor- 
  

   mously 
  developed 
  thin-walled 
  parenchyma, 
  which 
  persists 
  through 
  

   a 
  long 
  period 
  of 
  the 
  plant's 
  life. 
  They 
  are 
  especially 
  well 
  repre- 
  

   sented 
  in 
  Scilla, 
  Omithogalum, 
  Crocus, 
  Gladiolus 
  and 
  Oxalis. 
  

  

  