﻿514 
  Seve^'tii 
  Annual, 
  Report 
  of 
  tue 
  

  

  come 
  reconciled 
  to 
  its 
  new 
  environment 
  and 
  take 
  on 
  a 
  vigorous 
  

   gTOA\'tli. 
  The 
  tubercle 
  bacillus 
  from 
  the 
  bird 
  was 
  found 
  to 
  grow 
  

   with 
  difHeulty 
  in 
  nux-t 
  mammals, 
  and 
  the 
  bacillus 
  from 
  the 
  mam- 
  

   mal 
  in 
  birds. 
  The 
  bacilli 
  from 
  both 
  man 
  and 
  ox 
  were 
  found 
  to 
  

   produce 
  much 
  more 
  pronounced 
  lesions 
  in 
  guinea-pigs 
  than 
  in 
  

   rabbits, 
  but 
  the 
  genu 
  transferred 
  from 
  rabbit 
  to 
  rabbit 
  became 
  

   increasingly 
  fatal. 
  Again, 
  bacilli 
  from 
  human 
  sputum 
  were 
  found 
  

   to 
  operate 
  with, 
  diminished 
  force 
  in 
  the 
  bovine 
  animal, 
  producing 
  

   in 
  certain 
  cases 
  only 
  a 
  local 
  tubercle 
  in 
  place 
  of 
  a 
  generalized 
  dis- 
  

   order. 
  The 
  bacteriologists, 
  in 
  di-awing 
  attention 
  to 
  such 
  varia- 
  

   tions 
  in 
  experimental 
  cases, 
  have 
  become 
  the 
  perhaps 
  innocent 
  

   causes 
  of 
  a 
  crusade 
  against 
  all 
  sanitary 
  interference 
  with, 
  tubercu- 
  

   losis 
  in 
  our 
  herds, 
  and 
  the 
  lay 
  skeptics 
  have 
  practically 
  denied 
  

   any 
  possible 
  transference 
  of 
  the 
  disease 
  from 
  man 
  to 
  ox 
  or 
  from 
  

   ox 
  to 
  man. 
  To 
  correct 
  such 
  a 
  conclusion 
  it 
  is 
  important 
  to 
  bear 
  in 
  

   mind 
  some 
  established 
  tniths. 
  

  

  1. 
  This 
  rariahiUty 
  is 
  common 
  to 
  mierohcs 
  generally. 
  Certain 
  

   bacilli, 
  like 
  those 
  of 
  anthrax, 
  gTow 
  in 
  the 
  living 
  body 
  as 
  rods 
  only, 
  

   but 
  become 
  long 
  filaments 
  in 
  certain 
  artificial 
  media. 
  They 
  pro- 
  

   duce 
  no 
  spores 
  in 
  the 
  living 
  tissue, 
  but 
  do 
  so 
  readily 
  in 
  the 
  carcass 
  

   or 
  soil. 
  Transferred 
  from 
  ox 
  to 
  ox 
  they 
  are 
  generally 
  fatal, 
  but 
  if 
  

   grown 
  for 
  several 
  generations 
  in 
  guinea-pigs, 
  and 
  then 
  transfeiTcd 
  

   to 
  cattle, 
  the 
  resulting 
  disease 
  is 
  slight 
  (Burdon-Sanderson, 
  Duguid, 
  

   Greenfield). 
  Rabies 
  passed 
  from 
  dog 
  to 
  dog 
  is 
  almost 
  constantly 
  

   fatal, 
  but 
  if 
  passed 
  through 
  the 
  ape 
  and 
  then 
  back 
  to 
  the 
  dog 
  it 
  is 
  

   comparatively 
  harmless 
  (Pasteur). 
  In 
  both 
  these 
  cases 
  the 
  inocu- 
  

   lated 
  animals 
  become 
  immune 
  from 
  the 
  more 
  viimlent 
  germs, 
  

   showing 
  that 
  they 
  have 
  passed 
  through 
  the 
  actual 
  disease 
  in 
  an 
  

   unusually 
  mild 
  form. 
  The 
  later 
  system 
  of 
  Pasteur 
  is 
  founded 
  on 
  

   this 
  same 
  general 
  truth, 
  as 
  are 
  also 
  the 
  methods 
  of 
  lessening 
  the 
  

   pathogenesis 
  of 
  germs 
  by 
  subjecting 
  them 
  to 
  compressed 
  oxygen, 
  

   to 
  graduated 
  heating, 
  to 
  an 
  altered 
  chemical 
  condition 
  of 
  the 
  cul- 
  

   ture 
  medium, 
  to 
  antisepsis, 
  etc. 
  For 
  a 
  time 
  such 
  weakened 
  cul- 
  

   tures 
  often 
  retain 
  their 
  lessened 
  pathogenesis, 
  even 
  through 
  a 
  

   succession 
  of 
  cultures 
  in 
  a 
  susceptible 
  animal 
  body, 
  acting 
  as 
  if 
  

  

  