﻿CHEMOTHERAPEUTIC 
  AGENTS 
  — 
  WEINTRAUB 
  567 
  

  

  herapy. 
  It 
  is 
  in 
  this 
  respect 
  that 
  the 
  microbial 
  products 
  may 
  be 
  of 
  

   greatest 
  value, 
  since 
  even 
  at 
  this 
  early 
  stage 
  of 
  their 
  study 
  many 
  

   lew 
  avenues 
  of 
  exploration 
  have 
  been 
  opened 
  up. 
  Through 
  some 
  of 
  

   hese, 
  conversely, 
  will 
  come 
  better 
  understanding 
  of 
  the 
  physiology 
  

   md 
  nutrition 
  of 
  micro-organisms 
  and, 
  in 
  all 
  likelihood, 
  of 
  higher 
  

   mimals 
  also. 
  

  

  In 
  passing, 
  mention 
  may 
  be 
  made 
  of 
  another 
  possible 
  application 
  

   >f 
  these 
  agents, 
  namely, 
  in 
  the 
  control 
  of 
  certain 
  plant 
  diseases. 
  Very 
  

   ittle 
  has 
  been 
  done 
  along 
  this 
  line 
  and 
  its 
  practicability 
  cannot 
  yet 
  be 
  

   ; 
  orecast. 
  However, 
  the 
  few 
  experiments 
  which 
  have 
  been 
  carried 
  

   >ut 
  indicate 
  that 
  the 
  treatment 
  of 
  fungus-infested 
  soil 
  or 
  seeds 
  with 
  

   :ertain 
  bacterial 
  preparations 
  may 
  reduce 
  seed 
  decay 
  and 
  the 
  damping 
  

   )ff 
  of 
  the 
  seedlings. 
  

  

  Finally, 
  attention 
  should 
  be 
  directed 
  to 
  other 
  roles 
  of 
  the 
  antimicro- 
  

   3ial 
  substances 
  of 
  microbial 
  origin 
  which 
  may 
  possibly 
  be 
  of 
  far 
  

   greater 
  significance 
  than 
  any 
  eventual 
  therapeutic 
  application. 
  It 
  

   las 
  long 
  been 
  realized 
  that 
  countless 
  numbers 
  of 
  pathogenic 
  bacteria, 
  

   such 
  as 
  those 
  responsible 
  for 
  pneumonia, 
  diphtheria, 
  plague, 
  dysentery, 
  

   cholera, 
  tuberculosis, 
  etc., 
  gain 
  access 
  to 
  the 
  soil 
  via 
  the 
  excreta 
  or 
  

   remains 
  of 
  diseased 
  organisms. 
  Yet 
  the 
  soil 
  is 
  not 
  a 
  source 
  of 
  epi- 
  

   demics 
  of 
  these 
  diseases 
  and, 
  indeed, 
  the 
  pathogenic 
  micro-organisms 
  

   mnnot 
  be 
  recovered 
  from 
  the 
  soil 
  in 
  signficant 
  numbers. 
  It 
  is 
  hence 
  

   obvious 
  that 
  the 
  survival 
  of 
  such 
  forms 
  in 
  the 
  soil 
  is 
  very 
  limited. 
  The 
  

   suggestion 
  was 
  made 
  long 
  ago 
  that 
  other 
  soil-inhabiting 
  microbes, 
  an- 
  

   tagonistic 
  to 
  the 
  pathogens, 
  might 
  be 
  at 
  least 
  partially 
  responsible 
  for 
  

   the 
  rapid 
  disappearance 
  of 
  the 
  latter. 
  The 
  results 
  of 
  recent 
  work 
  lend 
  

   much 
  support 
  to 
  this 
  view, 
  so 
  that 
  it 
  appears 
  entirely 
  likely 
  that 
  anti- 
  

   microbial 
  agents, 
  such 
  as 
  those 
  described 
  here, 
  may 
  be 
  of 
  great 
  impor- 
  

   tance 
  in 
  the 
  natural 
  control 
  of 
  infectious 
  disease. 
  Possibly 
  this 
  may 
  

   apply 
  to 
  diseases 
  of 
  plants, 
  as 
  well 
  as 
  to 
  those 
  of 
  animals. 
  

  

  Certain 
  of 
  the 
  antibiotic 
  microbial 
  substances 
  may, 
  perhaps, 
  play 
  

   an 
  even 
  more 
  intimate 
  role 
  in 
  the 
  natural 
  control 
  of 
  some 
  superficial 
  

   infections 
  in 
  man. 
  The 
  skin 
  is 
  a 
  nearly 
  constant 
  habitat 
  of 
  certain 
  

   micro-organisms, 
  some 
  of 
  which 
  are 
  known 
  to 
  form 
  antimicrobial 
  pro- 
  

   ducts. 
  Whether 
  these 
  actually 
  serve 
  to 
  protect 
  against 
  skin 
  infections 
  

   is 
  not 
  known, 
  but 
  there 
  is 
  a 
  little 
  circumstantial 
  evidence 
  indicating 
  

   that 
  the 
  normal 
  skin 
  flora 
  may 
  be 
  absent 
  or 
  altered 
  in 
  cases 
  of 
  some 
  

   fungus 
  infections. 
  The 
  mouth 
  and 
  intestinal 
  tract, 
  too, 
  harbor 
  a 
  bac- 
  

   terial 
  flora 
  which 
  conceivably 
  could 
  be 
  of 
  importance 
  in 
  the 
  control 
  of 
  

   certain 
  infections. 
  

  

  It 
  is 
  hoped 
  that 
  this 
  brief 
  and 
  incomplete 
  account 
  of 
  the 
  antibiotic 
  

   substances 
  of 
  microbial 
  origin 
  will 
  have 
  served 
  to 
  call 
  attention 
  to 
  a 
  

   field 
  of 
  inquiry, 
  as 
  yet 
  merely 
  scratched, 
  whose 
  further 
  cultivation 
  

   may 
  well 
  be 
  expected 
  to 
  contribute 
  greatly 
  to 
  the 
  welfare 
  and 
  scientific 
  

   advancement 
  of 
  man. 
  

  

  