766 
Journal of Agricultural Research 
Vol. XXI, No. io 
The maximum longevity of the marked flies after liberation as shown by 
the records of capture was: Musca domesiica 15 days, Chrysomya macel- 
laria 17 days, Phormia regina 10 to 11 days, Ophyra aenescens 6 to 8 days, 
Sarcophaga spp. 11 to 12 days. 
While in the fourth experiment no marked flies were captured in the 
more distant traps (about 17 miles from the point of release), it is the 
authors’ belief that the limits of dispersion were not reached in that 
test and that where great numbers of flies are emerging constantly the 
distance traversed may be much farther than the maximum here deter¬ 
mined. 
The facility with which flies travel many miles emphasizes the im¬ 
portance of the general application of sanitary measures looking toward 
the suppression of fly breeding. 
