11 
tology  is,  in  our  opinion,  that  of  GIEMSA 
or  UNNA  with  differentiation.  We  obtained 
tvpical  preparations  with  both  stains.  The 
hematoxylin  also  may  give  important  details. 
SAHLFs  blue  is  splendid  for  perfunctory 
examination  of  sputum.  In  order  to  obtain 
more  details  by  this  stain,  it  is  neces¬ 
sary  to  differenciate  the  preparations  after 
colouring.  We  used  absolute  alcohol  or  al¬ 
cohol-acetone  (1/3).  This  process  does  not 
depend  on  a  special  fixation.  With  any  of  them 
the  result  is  very  good.  UNNA’s  blue 
(formula  of  BESSON)  and  LEISHMAN’s  stain 
give  good  structural  details  of  the  fungus. 
Thionin,  the  triacid  of  EHRLICH,  methylene- 
blue,  Z1EHLS  fuchsin,  eosin,  Sudan  III, 
“Neutralroth”,  VAN  GIESON  and  tincture 
of  iodine  were  used,  with  varying  results, 
for  the  systematical  study  of  the  morphology 
and  the  microchemistry  of  the  fungus. 
Artificial  cultures. 
In  the  begining  of  germination  the 
yeast  forms  prevail.  They  are  elliptical,  oval, 
polygonal  (center  of  the  culture),  rarely  sphe¬ 
rical.  These  forms  show,  as  a  rule,  two  dif¬ 
ferent  aspects:  a)  attached  to  each  other; 
or  b)  free  in  the  microscope  field.  The  former 
are  abundant  in  the  medium  of  GOROD- 
KOWA  or  in  the  old  cultures  of  Sabovraud 
with  maltose.  We  see  here  spherical  yeasts 
with  double  outline  and  an  involving,  sligh¬ 
tly  rosecoloured  border.  Protoplasm  uniformly 
stained  blue.  In  most  cases,  however,  these 
forms  show  only  the  double  outline  of  the 
membrane  stained.  The  protoplasm  does  not 
stain.  They  are  apparently  empty  cells.  The 
size  of  the  forms  varies  from  5  to  6  micra .  When 
deformed,  they  may  show  the  appearence  of  a 
mosaic 
These  different  aspects  of  the  parasite 
are  of  much-  interest  for  the  identification  of 
some  tissue  forms.  They  recall,  by  perfect 
ressemblance,  the  forms  of  the  “ Oïdium  brasi- 
liense”  in  the  lungs  of  man  and  monkey.  We 
understand,  therefore,  easily,  how  from 
them  may  derive  the  yeast  forms,  surroun¬ 
ded  by  a  border  and  found  in  the  human 
sputum.  We  must  not  confound  such  forms 
(especially  those  with  the  staining  limited  to 
the  membrane.)  with  the  involving  viscous 
net  of  certain  yeasts.  In  the  former  appears 
the  cell  itself,  in  the  latter  the  skeleton.  Where 
as  the  net  is  not  or  badly  stained,  cells  with 
protoplasm  having  strong  affinity  for 
colours  stain  blue  or  pale  violet.  From  these 
rectangular  forms  derive  the  rectangular 
pseudo-mycelian  forms,  seen  in  the  culture 
of  O.  brasiliense  and  in  the  foci  of  human 
pulmonary  lesions. 
The  free  forms  have,  as  a  rule,  the  clas¬ 
sical  aspect  of  yeasts.  They  appear  in  several 
shapes,  elliptical,  elongated  or  oval  and 
measure  about  3  micra ,  but  sometimes  up  to 
6  or  more.  In  the  old  cultures  on  Sabouraud 
with  maltose  or  in  the  water  of  carrot  cultu¬ 
res  they  may  even  attain  8  micra.  In  fresh 
cultures,  made  on  LOEFFLER’s  medium, 
they  recall  the  forms  found  in  the  sputa. 
Gemmation  is  the  rule.  We  also  observed  the 
so-called  “transversal  septation”.  It  is  a 
gemmation,  where  there  is  a  stainable  septum 
between  the  gem  and  the  mother-cell.  In  the 
classical  gemmation  sometimes  a  division  ot 
the  chromatin  is  seen.  First  it  becomes  elon¬ 
gate  ;  in  some  figures  we  see  a  long  thread 
uniting  the  chromatin  of  the  mother-cell 
with  that  of  the  daughter  cell  through  a  cel¬ 
lular  constriction.  The  thread  is  finally  seve¬ 
red,  the  constriction  becomes  complete  and 
both  the  new  cells  show  a  chromatin  gra¬ 
nule. 
We  call  attention  to  this  aspect  of 
yeast  cells  with  or  without  septa.  It  repre¬ 
sents  a  serious  objection  to  certain  systema¬ 
tical  subdivisions.  Here  the  distribution  of 
the  chromatin  is  typical.  At  first  undivided 
and  thick  in  the  center  of  the  yeast,  it  is 
fragmented  through  the  multiplication  of  the 
cells.  Agglomerated  subsequently  in  the  zone 
of  constriction,  it  is  divided  in  different 
portions  for  the  gem  and  the  mother  cell 
and  condensed  again  in  the  center  of  the 
newly  formed  cell.  It  must  be  known 
that  these  facts  are  observed  in  divisions 
with  or  without  septa.  However,  when  a 
