132 
ed  from  egg  clusters  which  I  had  thrice 
observed  on  the  back  of  Anthomyia  Hey- 
denii  W1ED. ,  sitting  on  horses,  long  before 
the  appearance  of  the  paper  refered  to.  I  kept 
a  specimen  on  a  pin,  but  saw  no  larva  emer¬ 
ging  and  now  this  specimen  has  been  lost. 
On  this  specimen  the  eggs  were  very 
close  together  and  so  small  that  they  might 
have  been  laid  by  another  fly  of  the  same 
kind,  but  this  is  not  the  case.  In  a  fazenda, 
where  Dr.  ARAGÃO  spends  his  holydays,  il 
was  noticed  that  spe-cimens  of  Dermatobia, 
caught  near  horses,  held  other  small  diptera 
in  close  embrace  between  their  legs.  He 
showed  me  this  while  1  was  staying  at  the 
place.  If  these  eggs  really  belong  to  Der¬ 
matobia,  as  these  observations  seem  to  prove, 
they  must  be  directly  laid  on  the  diptera 
which  absorb  blood  or  sweat,  such  as  the 
Anthomyia  caught  on  horses  and  cattle  by 
me.  They  may  easily  be  captured  by  Der¬ 
matobia  and  the  eggs  deposited  by  the  for¬ 
ward  bent  ovipositor.  This  also  explains  why 
people  in  the  affected  countries  attribute 
larvae  in  the  skin  to  mosquitos  or  even  to 
other  flies. 
1  have  two  other  much  older  observati¬ 
ons  on  the  same  point  to  report.  One  of  my 
collectors  told  me  that  once  while  in  the 
woods  he  distinctly  felt  a  sting  on  a  part 
of  his  skin,  from  which  three  days  later,  I 
extracted  the  smallest  Dermatobia  larva  1  had 
seen  up  to  then.  Another  time,  I  saw  a  pati¬ 
ent  suffering  from  typhoid  fever,  who  had  two 
bernes  in  the  sacrolumbar  region.  He  told 
me  that  one,  day  when  his  bed  was  made,  a  big 
blue  flv  was  found  crushed  in  it.  The  back 
of  this  hospital  in  which  another  case,  that 
of  a  nuise,  was  turned  toward  uncultivated 
grazing  grounds  and  the  windows  were  cons¬ 
tantly  open,  in  spite  of  a  great  number  of 
mosquitoes  coming  in  from  that  side. 
In  the  first  case  the  transmission  was 
probably  due  to  a  mosquito,  in  the  second 
to  a  fly,  which  might  even  have  been  a  Der¬ 
matobia,  carrying  the  eggs  of  another  one.  It 
is  quite  evident  that  if  the  eggs  are  laid  di¬ 
rectly  on  insects  caught  on  animals,  to  which 
they  often  return,  the  result  is  much  more 
likely  to  be  favourable  than  if  the  eggs  were 
laid  on  leaves  chiefly  visited  by  insects  which 
do  not  seek  out  larger  animals. 
It  would  also  be  necessary  to  stick  the 
eggs  on  the  leaves  by  their  cephalic  end,  so 
that  they  might  fix  themselves  by  the  caudal 
extremitiy  on  the  mosquito.  All  this  is  very 
unlikely  and  finds  no  analogy  among  other 
known  facts. 
The  statement  made  by  MORALES  in 
Guatemala  (that  the  eggs  are  laid  directly 
on  the  insects)  is  thus  confirmed.  TOWNS¬ 
END  also  shares  this  opinion. 
Concern  ng  the  egg  laying  of  Cutere- 
bra,  nothing  is  to  be  found  in  the  littérature. 
As  TOWNSEND  remarks,  the  large  number 
of  eggs  is  not  compatible  with  their  being 
deposited  on  the  host.  Some  years  ago,  I 
kept  a  female  Cuterebra  with  a  very  tame 
white  rat,  I  obtained  no  eggs  and  even  lost 
the  fly,  which  was  probably  eaten  by  the  rat. 
Another  time,  I  tried  to  obtain  eggs  by  a 
rather  strong  pressure  on  the  abdomen  of 
another  female  of  the  same  species,  but  with¬ 
out  result.  1  then  shut  the  fly  in  a  small 
wire  case.  Next  morning  I  found  the  wire 
netting  dotted  with  many  small  eggs.  They 
were  firmly  attached  by  their  base  and  had 
already  become  black.  They  were  observed 
for  some  time  but  no  larvae  emerged. 
The  cage  was  exhibited  twice  but  got  lost 
afterwards 
Additional  observations. 
The  present  paper  had  been  ready  for 
a  long  time,  when  I  found  an  opportunity 
to  make  some  new  observations  on  the  egg 
laying  and  development  of  Dermatobia  and 
also  on  the  existence  of  Oestrus  (Rhinoestrus) 
ovis  in  this  country.  I  publish  them  here  so 
as  to  complete  what  I  have  already  said. 
On  the  evening  of  Sept.  7th  1916,  while 
on  a  fazenda  neaf  Juiz  de  Fora,  I  saw,  by 
the  aid  of  a  field  glass,  two  Dermatobia  flies 
siting  on  calves  at  the  edge  of  a  wood.  Soon 
after,  they  alighted  on  the  horses  of  our  car¬ 
riage  and  were  caught.  One  of  them  contai¬ 
ned  a  great  many  eggs.  Shortly  afterwards, 
