31 
foci  of  red  bloodcorpuscles.  They  prove 
that  the  presence  of  the  Oidium  in  the  tis¬ 
sue  does  not  result  from  a  cadaveric  invasi 
on  and  postmortal  vegetation  of  a  common 
fungus  of  the  ordinary  bronchial  flora,  without 
relation  to  the  human  disease.  They  indicate 
a  close  connexion  with  the  evolution  of  the 
signs  of  disease  in  the  individual,  from  whom 
these  sections  were  obtained  (congestive 
form).  The  important  thing  is  to  recognise 
the  parasite  in  these  foci.  We  give  drawings 
and  photographs,  with  oil  immersion  of  forms 
taken  from  tissue  and  from  artificial 
cultures,  which  need  no  discussion.  Certain 
sections  with  little  invasion  of  parasites, 
examined  with  low  power,  remind  one, 
mutatis  mutandis ,  of  pulmonary  sections  with 
microscopical  foci  of  bacillary  tuberculosis 
in  its  granulation  form. 
However,  the  anatomical  characteristics 
of  the  tubercle  are  not  observed.  The  sec¬ 
tions,  stained  by  Giemsa’s  method  (with  dif¬ 
ferentiation)  and  by  picrocarmine-indigo-fu- 
chsin,  show  the  structure  of  these  foci  more 
clearly.  The  aspect  is  remarkable.  It  seems 
impossible  to  distinguish  the  structure  of 
the  foci,  when  stained  by  hematoxylin-eosin. 
They  resemble  here  a  uniform  and  finely 
granulated  mass  of  rose  colour.  On  exami¬ 
ning  with  immersion,  however  we  see 
their  real  constitution.  By  the  methods  of 
FONTES  or  Z1EHL-NEELSEN  we  see  neither 
KOCH’s  bacillus  nor  giant-cells,  but  exclu¬ 
sively  the  resisting  forms  of  the  Oidium. 
And  if,  to  those,  who  are  not  yet  used  to 
the  observation  of  this  aspect  of  the  fungus, 
the  foci  are  not  favourable  localisations  for 
recognizing  the  object  seen,  thery  are  inter¬ 
mediary  zones  where  any  doubt  ceass 
(see  photographis  and  drawings).  The  hy¬ 
pothesis  of  MUCH’s  granular  tuberculosis 
which,  in  the  tissues  more  than  in  the  sputa, 
only  the  trained  eye  is  able  to  distinguish, 
does  not  come  in  here.  We  never  succeeded 
in  observing  such  elements.  Leaving  aside 
this  negative  proof,  we  have  that  of  the  ex¬ 
perimental  inoculation  of  the  guinea-pig. 
MUCH's  tuberculosis  makes  the  guinea-pig 
tuberculous.  We  never  obtained  this  result 
with  sputum,  nor  with  triturated  suspect 
organs,  obtained  by  post-mortem.  In  these 
small  foci  the  pulmonary  tissue  is  hardly  re¬ 
cognised  between  the  network  of  parasites. 
Around  these  foci,  as  well  as  around 
the  larger  ones,  the  alveoli  are  full  of  para¬ 
sites,  leucocytes  and  red-blood  corpuscles, 
interwoven  in  a  dense  network  of  fibrin.  In 
some  no  open  space  remains,  in  others  there 
is  always  some  air  in  the  alveolar  cavities. 
The  same  happens  in  the  bronchi.  Only 
few  epithelial  cells  are  seen.  There  is  no 
desquamating  alveolitis.  The  capillaries 
appear  dilated  and  full  of  blood.  In  the  re¬ 
gion  of  the  foci,  the  intra-alveolar  septa  dis¬ 
appear  or  become  very  thin.  Outside  of 
these  foci,  there  are  a  few  places  where  the 
alveoli  appear  dilated. 
In  certain  foci  there  are  places,  where 
the  tissues  appear  necrotic,  with  an  indica¬ 
tion  of  cavities  forming.  In  these  parts  we 
see  classical  yeast  forms  with  double  outline 
and  gems.  Leucocytic  infiltrations  around  the 
bronchi  or  the  blood  vessels  are  rare  and, 
whenever  found,  quite  small.  The  alveolar 
epithelium  is  normal  in  certain  parts.  In 
other  parts  it  is  found  slightly  hypertrophic 
and  invaded  by  lymph  elements.  Dust 
cells  are  abundant  and  well  marked.  The 
histology  of  microscopical  foci  shows  cliarac- 
teristical  features.  There  are  no  real  subdivi¬ 
sions  in  zones,  as  in  tuberculosis,  syphilis, 
etc.  The  presence  of  the  parasite  in  the  pul¬ 
monary  tissue  causes,  beside  the  natural  leu¬ 
cocytic  reaction,  phenomena  of  congestion. 
In  these  foci  there  is  no  lymphocytosis,  but 
exclusively  leucocytosis,  and,  especially,  a 
great  number  of  red  bloodcorpuscles,  inside, 
about  and  even  distant  from  the  chief  locali¬ 
sation  of  the  parasite. 
Diagnosis. 
The  diagnosis  of  the  oidiosis  finds  now¬ 
adays  a  certain  and  unerring  confirmation 
in  the  microbiological  and  anatomo-clini- 
cal  facts.  Beside  many  others,  there  are  two 
principal  sources  of  error,  which  we  must 
