Hoffmann  found  tubercle  bacilli  in  2  of  4  flies  captured
in  a  room  occupied  by  a  tuberculous  patient,  and  also  in
the  excreta  of  flies  scraped  from  the  walls  and  furniture  of
the  room.  Lord2  found  virulent  bacilli  in  flyspecks,  but
could  not  induce  the  disease  by  causing  guinea  pigs  to
breathe  air  drawn  over  infected  specks.  Hay  ward3  demon-
strated living  bacilli  in  flyspecks  after  the  flies  had  been
fed  on  sputum  in  such  a  way  as  to  preclude  the  possibility
of  the  infection  of  their  feet  or  bodies.  Andre4  demon-
strated tubercle  bacilli  in  the  excreta  of  flies  by  inoculation
tests,  and  he  found  that  they  appeared  in  the  feces  about
six  hours  after  feeding  and  continued  for  five  days.  Flies
may  also  become  infected  by  eating  tuberculous  dust.
Graham-Smith5  after  feeding  flies  for  several  days  on
syrup  infected  with  a  culture  of  human  tubercle  bacilli  de-
termined that  the  bacilli  may  "  be  present  in  the  crop  for
3  days.  In  the  intestines,  however,  they  may  be  found  for
much  longer  periods,  being  present  in  considerable  numbers

1  Centralbl.  f.  Bakteriol.  (etc.),  I,  Abt.,  Jena,  1910,  LIII,  486.
2  Lord,  Boston  M.  &  S.  J.,  1904,  CLI,  651.
3  Hayward,  N.  York  M.  J.  [etc.],  1904,  LXXX,  643.
4  Andre",  6th  Internat.  Cong,  on  Tuberc.,  Wash.,  1908,  I,  162.
5  Graham-Smith,  Rep.  to  Local  Gov.  Bd.,  1910,  No.  40.
