a  small  quantity  of  chromatin  in  the  center 
of  the  protoplasma;  at  other  times  the  chro¬ 
matin,  if  present,  is  subdivided  or  diffuse. 
In  old  cultures  the  mycelium  is  pale  and 
uniformly  stained.  When  the  mycelium  is  fine 
and  without  septa,  we  frequently  see,  at  inter¬ 
vals,  small  masses  of  chromatin  belonging 
to  the  cell,  from  which  springs  the  my¬ 
celium.  These  forms,  found  in  cultures, 
remove  serious  doubts  about  similar  forms, 
found  in  smears  of  organs  in  post-mortem 
examination.  Nor  would  it  be  the  first  time 
that  a  mycelium  was  confounded  with  the  fi¬ 
lamentous  form  of  certain  bacilli  (see  BON- 
CHI,  JUNGANO,  etc.).  This  cause  of 
error  in  autopsies  is  not  to  be  forgotten.  The 
examination  of  these  fine  mycelia  in  different 
preparations  leads  to  an  exact  notion  of 
the  importance  of  the  small  masses  of  chro¬ 
matin  described  above.  They  give  birth  to 
important  elements  of  the  fungus.  The  proto¬ 
plasm  around  this  chromatin  tends  to  con¬ 
dense  itself  and  is  more  deeply  stained 
than  in  other  parts  of  the  mycelium.  Shortly 
afterwards  appears  the  first  sign  of  a  membra¬ 
ne,  which  rapidly  acquires  a  distinct  outline. 
The  endoconidia  are  formed.  After  the  my¬ 
celium  is  broken  or  divided  (which  is  the 
rule),  the  new  phase  of  the  cycle  of  the 
fungus  begins.  The  division  of  the  mycelium 
varies.  The  cylindrical  or  rectangular  forms 
do  not  obey  to  a  regular  systematical  divi¬ 
sion.  From  dichotomisations  and  tricho- 
iomisations  to  the  most  unexpected  divi¬ 
sions  may  be  found. 
The  terminations  of  the  mycelium  are 
neither  constricted,  nore  more  voluminous. 
The  articulations  of  the  mycelian  elements 
also  are  not  imbricated  and  might  be  conside¬ 
red  articulations  by  simple  contact.  The  endo¬ 
conidia  are  oval  or  rectangular.  The  septa 
of  the  mycelium  disappear  in  old  :ultures. 
The  best  and  most  common  aspect  is  that 
which  resembles  rectangular  elements,  united 
at  the  ends  where  the  mycelium  is  very 
brittle. 
Strange  forms. 
These  forms  are  morphological  aspects 
of  the  parasite,  apt  to  lead  the  observer 
astray.  Careful  attention  helps  a  good  deal  to 
understand  them.  In  the  cultures  of  poor  media 
as,  for  instance,  the  exsudation  of  serous 
membranes,  one  finds  sometimes  mostly 
coccuslike  forms  with  double  outline,  pro¬ 
ducing  gems  or  not.  There  are  forms  which 
recall  those  of  the  Adenomyces  of  the  human 
lyi  )hglands.  These  are  special  forms  of  bacil¬ 
lary  type  in  which  various  granulations  are 
seen.  We  give  some  photographs  of  them. 
There  are,  furthermore,  forms  “en  navet¬ 
te”. 
We  also  find  bacilli  with  an  irregular 
dilatation  at  one  of  the  extremities,  in  which 
an  intensely  stained  granulation  is  seen.  The 
bacillus  is  septated  a  little  above  the  dilatati¬ 
on.  This  polymorphism  is  not  at  all  strange, 
as  we  know,  that  it  is  no  exception  amongst 
the  infinitely  small  beings.  Amongst  many 
others  the  MUCH-MELLER’s  microbe  is  an 
eloquent  example  of  this,  and,  were  it  not 
for  the  pure  origin  of  the  culture,  one  might 
declare  it  a  whole  scale  of  various  micro¬ 
bes. 
The  hanging-drop  cultures  are  well 
suited  to  the  study  of  the  biology  of  the 
Oidium  brasiliense.  We  always  preferred  the 
glucosebroth  or  GORODKOWA's  medium. 
The  aspect  of  the  fungus  observed  in  this 
way,  is  the  same,  as  in  stained  preparations. 
In  animals.— Experiments. 
Experimental  disease. 
This  is  one  of  the  most  interesting  chap¬ 
ters  of  the  biology  of  the  fungus.  White 
and  gray  rats,  mice,  guinea-pigs,  rabbits  and 
monkeys  {Hap  ale  penicillata,  Callithrix 
iacchus,  and  Alouata  fusca)  always  die,  when 
inoculated  bv  any  way  with  culture  emulsion 
of  Oidium  brasiliense. 
We  obtened  positive  results  by  the  fol 
lowing  ways: 
a)  intermuscular 
b)  intravenous 
