-  131 
I  found  out  that  the  females  of  Cuterebra 
a  nd  Pseudogametes  also  have  an  ovipositor, 
though  it  is  shorter,  the  males  a  well  formed 
genital  structure.  There  is  a  great  analogy 
between  their  organs  and  those  of  the  do¬ 
mestic  fly.  The  eggs  ere  always  shaped  like 
bananas  and  have  a  lid  at  one  of  the  extre¬ 
mities.  In  one  female  Dermatobia  1  counted 
over  Ç00  eggs  and  NE1VA  found  a  mean 
number  of  750-800.  TOWNSEND  calculated 
that  there  are  about  10.000  ripe  eggs  in  a 
species  of  Cuterebra  he  examined;  the  eggs 
are  very  small  in  proportion  to  the  size  of 
the  animal. 
On  the  whole,  there  are  more  female 
than  male  specimens  of  Dermatobia  and 
Cuterebra ,  caught.  Of  Pseudogametes,  at  least 
of  the  species  semiater  there  are  more  males 
than  females  seen.  These  Oestrids  fly  per¬ 
fectly  but  are  rather  lazy  and  remain  seated 
in  the  same  place  for  hours.  1  have  seen 
Dermatobia  absorb  liquids  by  means  of  the 
proboscis.  It  does  not  seem  to  mate  in  the 
first  days  after  ecdysis.  All  our  Oestridae  buzz  Í 
and  a  Cuterebra ,  shut  in  a  breeding  glass, 
makes  a  noise  like  a  Bombus. 
I  have  often  witnessed  the  ecdysis  ot  j 
Dermatobia  and  even  had  it  cinematograph-  | 
ed.  The  fly  dislocates  the  lid  at  the  end 
of  the  puparium  by  violent  efforts  of  the 
ptilinum  which  swells  to  the  size  of  the  head 
and  works  in  andyout  with  rhythmic  motion. 
By  applying  pressure,  the  ptilinum  may  be 
extruded  even  some  time  after  tne  ecdysis. 
On  leaving  the  pupa  the  fly  walks  briskly  ; 
the  wings  take  a  little  time  to  dry  and  fill 
with  air;  the  rest  of  the  body  also  requires 
some  time  to  dry  and  assume  its  na¬ 
tural  colour  and  consistance. 
As  in  other  díptera,  the  ecdysis  is  rarely 
made  in  darkness  After  waiting  the  neces¬ 
sary  time  33-37  days  according  to  NEIVA’s 
and  own  observation,  the  ecdvsis  may  be 
rapidly  obtained  by  exposing  the  pupa  to 
sunlight  after  keeping  it  in  a  dark  place,  or 
even  by  lifting  the  lid  and  breathing  on  the 
imago,  as  BRAUER  advises.  Unless  I  am 
mistaken,  the  pupa  state  of  a  Cuterebra  apica- 
lis  bred  by  me  one,  lasted  eighty  days;  for 
Rogenhofera  grandis  it  may  amount  to  forty 
three  days,  as  observed  by  Berg. 
Dermatobia  was  raised  several  times 
from  larvae  obtained  from  animals  by  SCH- 
MALZ,  LUTZ,  YOUNG,  NElVAand  others. 
They  can  be  collected  after  leaving  their  host, 
or  while  they  are  doing  so,  or  comtempo- 
rary  larvae  may  be  extracted.  1  prefer  to 
raise  them  in  saw-dust.  They  burrow  at  once 
and  the  external  covering  is  formed  in  a 
few  days  by  the  dessication  of  the  outer  skin. 
They  will  even  metamorphose  entirely  ex¬ 
posed,  if  not  allowed  to  get  too  dry.  Cute¬ 
rebra  and  its  allied  genera  do  not  seem  to 
offer  greater  difficulty,  if  larvae  in  the  last 
stage  (or  living  hosts  which  allow  one  to 
wait  for  the  ripening  of  the  larvae)  are  ob¬ 
tainable. 
Still  have  a  few  words  to  say  on  the 
egg  laying  of  our  Oestridae-,  up  to  now  it 
has  not  been  witnessed,  nor  have  recently 
laid  eggs  and  larvae  been  found.  It  may  ho¬ 
wever  be  affirmed  that  they  are  oviparous  ; 
many  specimens,  some  of  which  have  been 
caught  by  me  while  hovering  around  animals 
with  extended  ovipositor,  were  examined 
and  excluded  all  doubt  on  this  point.  They 
never  contained  any  larvae  in  or  outside  the 
egg  shells.  Dermatobia  is  not  commonly 
seen  flying  in  day  time,  but  in  the  course 
of  some  years  1  got  more  than  a  dozen  spe¬ 
cimens,  which  were  caught  on  horses  toge¬ 
ther  with  Tabanids.  I  myself  have  seen  sever¬ 
al  specimens  flying  round  horses  and  once 
round  a  person,  and  picked  three  live  speci¬ 
mens  from  a  very  tame  black  bull;  they 
were  noticeable  as  the  brick  red  colour  of 
their  eyes  contrasted  with  the  dark  skin  of 
the  animal.  All  these  specimens  contained 
well  developed  eggs  but  no  formed  larvae. 
Accordiing  o  GONÇALEZ-RINCONES 
and  SURCOUF  the  eggs  are  laid  on  leaves 
from  which  they  pass  to  the  venter  of  mos¬ 
quitos,  by  adhesion  and  infect  animals  stung 
by  them.  In  the  Welcome  Institute  in  Lon¬ 
don,  I  saw  a  specimen  of  the  lanthinosoma 
Lutzi  with  a  cluster  of  eggs;  as  I  expected,  the 
seemed  to  have  been  deposited  on  the  in¬ 
sect  itself.  They  could  not  been  distinguish- 
