7 
the  Oïdium,  brasiliense ,  in  the  artificial  cultu¬ 
res,  are  in  fact  yeast  cells  and  are  alike  or 
similar  to  those  we  find  in  the  tissues  and 
in  the  sputum.  This  aspect  of  the  parasite  is 
not  at  all  strange,  as  we  know  it  to  be  an 
Oïdium. 
The  photographic  prints,  which  accompa¬ 
ny  this  paper,  show  the  mycelian  form  of 
the  fungus.  They  are  true  mycelia,  not  pseu- 
do-mycelian  forms,  while  yeasto  — not  in  the 
old  sense  but  according  to  modern  mycology- 
are  unicellular  fungi  “which  in  no  stage  of 
evolution  show  true  mycelia’''  (GU1LL1ER- 
MOND).  Besides,  there  are  biological  cha¬ 
racteristics,  •«.hich  include  them  into  the  „4s- 
comycetes. 
The  O.  brasiliense  is  also  by  no 
means  the  first  example  of  a  fungus,  which, 
while  developping  normally  in  mycelian  form, 
presents,  at  a  given  momert  of  its  life-cycle, 
on'y  yeast-forms.  This  morphological  dupli¬ 
city,  though  characteristical  for  the  family  of 
Oidiaceae,  may  be  found  elsewhere,  as  shown 
by  the  basidiospores  of  some  Basidiomyce- 
tes. 
There  is,  also  the  classical  exemple  of 
“ Dernatium  pullulons”. 
This  fungus  with  highly  differentiated 
mycelium  may,  in  certain  conditions,  mul¬ 
tiply  exclusively  by  yeastforms.  The  adap¬ 
tation  to  the  new  form  is  so  com¬ 
plete,  as  to  make  it  difficult  to  again  obtain 
a  mycelium.  In  this  special  case  we  observe 
in  microscopical  morphology,  what  SABOU- 
RAUD  noted  in  the  macroscopical  morpho¬ 
logy  of  certain  tineae.  The  pleomorphous  forms 
of  the  Trichophyta  undoubtedly  mav  become 
constant  in  certain  media  of  culture,  but 
these  facts  are  still  liable  to  new  interpreta¬ 
tions.  The  outer  aspect  of  the  cultures  alrea- 
dv  helps  to  distinguish  it  from  the  Endomy- 
ces  albicans.  On  potatoc  for  instance,  the 
Oidium  brasiliense  gives  dry,  mealy  and  dis¬ 
tinctly  wrinkled  cultures.  The  Endomyces 
gives  humid,  viscous  cultures  without  wrin¬ 
kles.  To  the  difference  in  macroscopical  mor¬ 
phology  corresponds  an  evident  divergence 
of  the  microscopical  morphology.  On  potatoe 
the  Endomyces  gives,  as  a  rule,  yeast  forms 
which  are  prevailing  in  the  preparation  (smears 
etc.).  The  contrary  happens  with  the  O.  bra¬ 
siliense,  in  the  potatocultures  of  which  the 
mycelian  forms  prevail.  The  table  of  fermen¬ 
tations,  given  at  the  end  of  this  paper,  also 
furnishes  a  good  standard  of  palpable  diffe¬ 
rences.  This  table  may  be  compared  with 
that  given  by  CASTELLAN1  in  the  “Journal 
of  tropical  Medicine”  of  1911.  For  establishing 
his  table  of  fermentation  this  author  studied 
13  varieties  of  Endomyces  albicans. 
We  abstain  from  further  comment.  — The 
creosote  medium  does  not  furnish  any  positive 
information,  as  regards  the  differentiation  of 
the  Endomyces  albicans ,  in  spite  of  the  asser¬ 
tion  of  some  authors.  It  is  a  mistake  to  declare 
it  impossible  to  obtain  cultures  of  this  pa¬ 
rasite  in  a  medium  with  creosote.  All  depends 
on  the  percentage  of  this  substance  in  the 
artificial  medium.  With  0,5  %  we  failed  to 
obtain  the  culture,  but  with  0,01  °/o  we  got 
good  cultures  of  Endomyces  albicans.  The 
same  is  true  for  the  “ Oidium  brasiliense” . 
The  Oidium  brasiliense  differs  also  from  the 
Endomyces  in  the  cultures  on  carrot,  agar, 
(2  o/o)  gelatine,  SABOURAUD  with  maltose, 
and,  chiefly,  on  alkaline  and  acid  media. 
The  studies  of  VUILLEMIN  also  show 
the  nature  of  the  Endomyces  albicans.  In  old 
cultures  of  this  fungus  the  author  found  asa 
and,  therefore,  rightly  included  it  in  the  As- 
ccmvcctes.  We  never  found  asci  in  the  cultu¬ 
res  of  the  Oidium  brasiliense ,  nor  even  in 
the  artificial  cultures  of  GORODKOWA. 
Any  doubt,  still  remaining,  is  dispelled  dy  the 
high  pathogenic  power  of  the  parasite  under 
study.  The  bucco-nasal  inoculation  by  pain¬ 
ting  the  mucosa  without  scarification  is  suf¬ 
ficient  for  killing  monkeys  or  rabbits.  All 
the  common  laboratory  animals  are  sensible 
to  the  Oidium  brasiliense ,  whatever  way  of 
inoculation  may  be  used. 
The  inclusion  of  the  O.  brasiliense  into 
the  Oidiaceae  can  only  be  appreciated  after 
reading  this  paper  to  the  end.  We  recom¬ 
mend  the  lecture  of  the  paper  of  GOUGE- 
ROT  &  VAUCHER  (1910),  as  it  is  impossi¬ 
ble  to  resume  it  here. 
