-  8 
Natural  occurrence. 
Our  researches  did  not  give  any  definiti¬ 
ve  solution  of  this  question.  The  cases  of 
amygdalitis,  laryngitis  and  pharyngitis,  in 
which  we  succeeded  in  isolating  the  parasi¬ 
te,  lead  us  to  the  belief  that  its  forms  of  re¬ 
sistance  exist  freely  in  the  natural  surroun¬ 
dings.  Expelled  with  the  sputum  by  cou¬ 
ghing  and  imbedded  in  certain  substances,  it 
may  live  in  the  form  of  spores  till,  coming 
in  contact  with  the  tonsils,  the  pharynx,  the 
bronchial  tubes  or  the  intestine,  it  may  de¬ 
velop  and  multiply  under  favourable  condi¬ 
tions. 
We  already  began  researches  for  eluci¬ 
dating  this  obscure  side  of  the  disease.  We 
do  not  believe,  however,  that  for  the  O.  bra - 
siliense  there  are  intermediate  hosts  in  the 
actual  signification  of  the  word  :  at  best, 
perhaps  some  reservoirs  of  virus,  as  for  the  ! 
species  of  Sporotrichum  (QOUGEROT). 
Scrapings  of  ulcers,  pus,  skin,  sections,  scales, 
etc.  never  gave  us  cultures  of  the  O.  brasi- 
liense. 
Artificial  cultures. 
Macroscopical  aspect. 
When  first  isolated  from  the  sputum  or 
from  the  lesions  with  the  precautions,  neces¬ 
sary  for  such  cultures,  the  Oïdium  brasiliense 
presents  an  unequivocal  general  aspect, 
which  always  is  quite  the  same.  The  best 
medium  for  the  development  of  the  parasite 
is  Sabouraud  with  maltose  in  laboratory  tempe¬ 
rature.  After  48  hours  of  growth  in  a  balloon 
of  ERLENMEYER,  the  culture  presents,  in 
this  initial  stage,  with  its  dirty  gray  colour  and 
light  cover  of  white  down,  a  chamois-like 
aspect,  looking  like  a  fine  net  piled  up, 
without  a  rim  and  elevated  in  the  center  of  the 
culture.  Slightly  humid  in  the  beginning,  it 
soon  becomes  dry  in  the  succession  of 
days.  In  first  instance  the  folds  become  more 
accentuated,  the  filaments  (fructification  of 
the  culture)  and  the  velvety  and  tomentous 
aspect  prevail  more  and  more,  and  give 
an  unmistakable  aspect  to  the  culture.  There 
is  a  manifest  regularity  in  the  distribution  of 
the  folds  and  the  fluffyness.  The  culture  in¬ 
creases  in  size  and  may  attain  the  borders 
of  the  artificial  medium. 
Potatoe. 
After  24  or  48  hours  the  stroke  cultures 
show  the  crinkling  of  the  surface,  which,  a 
little  later,  is  covered  by  a  whitish  and  mealy 
film  similar  to  very  small  hairs.  The  culture 
has  a  velvety  aspect.  After  some  time  a  thick 
pellicle  appears  on  the  water  of  the  tube. 
Carrot. 
The  culture  is  already  exuberant  after 
24  hours.  One  of  our  plates  gives  an  exact 
idea  of  its  appearance.  It  is  dirty  yellow,  with 
velvety  aspect  and  very  wrinkled.  In  the 
course  of  evolution  the  folds  become  accen¬ 
tuated  and  distant,  being  high  and  numerous. 
Some  folds  are  so  elevated,  as  to  touch  the 
inner  wall  of  a  tube  with  a  circumference  of 
3-4  centimeters.  These  cultures  are  very  apro- 
priate  for  the  diagnosis  and  the  study  of 
certain  mycelia. 
The  water  of  the  tubes  of  these  cultures 
contains  abundant  mycelian  elements  of  va¬ 
rious  aspect  and  is  covered  by  a  brownish 
pellicle. 
Milk. 
The  coagulation  begins  on  the  sixth  day. 
Complete  coagulation  on  the  12th  day  with¬ 
out  change  of  colour. 
Simple  gelatine. 
Liquefaction  within  ’2  or  14  days  with 
formation  of  a  thick  darkbrown  pellicle  at 
the  surface. 
Sabouraud  with  creosote  (0,01  o/0). 
Development  retarded.  The  old  cultures 
resemble  those  on  Sabouraud  with  maltose. 
We  call  the  readers  attention  to  these  cul¬ 
tures.  When  a  higher  percentage  of  creosote 
is  added,  the  parasite  does  not  grow. 
With  0,5,  0,1  or  0,2  °/0  there  are  not 
even  traces  of  development  of  the  parasite. 
