SCIENCE AND INDUSTRY. 
(also some of the pup) being carefully examined for the presence of 
worm larve in later stages of development. In addition, captured flies 
were dissected and results noted. 
Worms were found in various situations, being present in the 
abdomen, thorax, and head, and when sufliciently developed to escape 
from infected flies, they were to be found in the proboscis. 
The following species of Musca were used in our work: M. domes- 
tica (the house fly); M. fergusoni, Instn. and Bancr.; M. vetustissima, 
Walker; M. terraregine, Jnstn. and Baner.; M. hilli, Instn. and 
Baner.; all but the first-named being “ bush flies ” or “ cattle flies.” We 
also utilized the stable fly (Stomowys calcitrans), flesh flies (Sarcophaga 
misera, Walker), certain metallic flies (Pseudopyrellia sp.), and the 
common blowfly (Anastellorhina augur). All species were found, either 
naturally or under experimental conditions, to be able to harbor larve 
of one or more of the species of Habronema, acting in the capacity of 
intermediate hosts, and not merely as mechanical carriers of the para- 
sites. 
Stomoxys was found to be capable of harboring only H. micro- 
stoma; while the five species of Musca, together with Sarcophaga and 
Pseudopyrellia were suitable intermediate hosts for both. H. musca 
and H. megastoma, but not for H. microstoma. 
The blowflies became parasitized by transferring the young larve 
from meat to infected horsedung, 7 per cent. of the emerging flies being 
found to harbor immature Habronema worms, but to which species they 
belonged could not be satisfactorily determined. It was not ascertained 
whether these nematodes could complete their larval development in the 
blowfly. Since blowflies do not normally breed in horse manure, they 
are of little importance as transmitters of the worms under notice. * 
H. musce was found to be much more common than //. megastoma 
in flies. Sometimes both species occurred in the same insect. 
The following table gives a summary of our results with flies in 
which statistical record was kept :— 
CapTuRED FLIEs. 
Species. No. Examiued. | Noinfected withy | Tereen'are 
Musca domestica .. gi A 122 10 7°6 
M. fergusoni Ot #e = 1,176 26 2°2 
~ M. vetustissima .. Pe: nj 280 14 5:0 
M.terreregine .. id op 21 1 4:8 
Brep Frras. 
M. domestica ba a she 165 | * 98 59* 
M. fergusont ah ft: ve 58 55 . 95 
M. vetustissima a Be 60 60 100 
M.terreregine .. ts Re 10 10 100 
M.hilli .. sf a4 re 12 10 8°3 
Pseudopyrellia sp. ay a 6 6 100 
Sarcophaga misera aE “43 255) 5) ll 44 
Anastellorhina augur re st 28 2 71 
Hill’s record for infected house flies was also 7.6 (14 parasitized 
out of 182 examined in Melbourne), all with H. musc@ alone. Ransom 
found 28 per cent. infected (39 out of 187) in certain United States 
'* Omitting one experiment in which the horsedung was almost certainly not infected, the figures were 
respectively 115 examined, 98 infected, percentage 82. 
37° 
