sites was noted, and in the fresii condition alniost every one 
shewed l'.ie varions ptiases of simple longitudinal division. These 
appearances werc contirined by examining a large number of 
stained specimens. Up to the tenth day the flies were swarming 
with these long forms tmdergoing division. A study of these par¬ 
asites in the fresh condition clearly demonstrated that any one of 
theni just comniencing division complétés the process in from ten 
to fifteen minutes. It can be easily undeistood that if a fly in- 
gests twenty of these long forms they will in the course of a 
fcw days mtiltipl}' to many hundreds of thousands. These facts, 
\\ hi( h hâve now bcen proved by rigid experiments, at once ex¬ 
piait! why it is that the majority of bazaar flies contain these 
dividing forms, which hâve been mistaken for parasites with two 
flagella; the infections produced in mv cages however were never 
so intense as those seen in wild flies. The explanation of this 
différence is quite simple. It lias been proved above that clean 
hatched flies ingest these long flagellated forms of Herpetomon- 
as m.uscae domesticae in varying numbers when they feed on 
infected food, my flies were only fed once on such food. It is 
onlv necessary to visit the bazaar méat shops to see that flies 
constantlv move from one piece of méat to another, and dtiring 
the dav they may feed on several different pièces. At each feed 
they are liable to ingest fresh flagellâtes which hâve been pas- 
sed out by other flies, so that instead of ingesting a hundred 
siK'h forms they may stick up thousands, and this may be repeat- 
ed on each succeeding day. It has been shewn above, that these 
long flagellâtes go on dividing indefinitely, and may be présent 
in the mid gut of a fly up to the tenth day, so that in a wild 
flv the entire alimentary tract may be one mass of long flagellâ¬ 
tes. This is one of the commonest appearances seen in the flies 
from the bazaar méat shops, yet it is remarkable that they do 
not appear to be injtired to any appréciable extent. I Iiawe how¬ 
ever foLind that flies with such heavy infections are never satis- 
fied with one feed during the day, and that they are practically 
in a starved condition. The reason for this was readilv fotind by 
examinintï clean control flies fed at the same tinte as the infected 
flies. In the latter the food ingested dtiring the previous twelve 
hours had almost entirely disappeared, whereas in the control 
flies much of it still remained. It ivas clear that the swarms of 
flagellâtes, which after each feed pass up to where the food is, had 
