404 
C. GOEDON HEWITT. 
appendages and transferred them subsequently to the culture 
media, but they were not recovered from those flies which 
were kept in confinement for twenty-four hours ; a large 
number of flies, however, were not used. 
Dr. Kerr, of Morocco, in a paper on “ Some Prevalent 
Diseases in Morocco,” i-ead before the Glasgow Medico- 
Chirnrgical Society (December 7th, 1906), described epidemics 
of Syphilis where, according to the author, the disease was 
spread by flies which had been feeding upon the open sores 
of a syphilitic patient. 
Howard (1909) calls attention to an important investigation 
carried on by Esten and Mason (1908) on the role which flies 
play in the carriage of bacteria to milk. The flies were caught 
by means of a sterile net; they were then introduced into a 
sterile bottle and shaken np in a known quantity of sterilised 
water to wash the bacteria from their bodies and to simulate 
the number of organisms that would come from a fly falling 
into a quantity of milk. They summarised their results in the 
table given on p. 403. 
From that table it will be seen that the numbers of 
bacteria carried by a single fly may range from 550 to 
6,600,000, while the average number was about 1,222,000. 
Commenting on these results, the authors state that “ early in 
the fly-season the numbers of bactei’ia on flies are compara- 
tively large. The place where flies live also determines 
largely the numbers that they carry.” From these results the 
importance of keeping flies away from milk and other food 
will readily be seen. 
VIII. Flies and Intestinal Myiasis. 
The larvae of M. domestica and its allies are frequently 
the cause of intestinal myiasis and diarrhoea in children. The 
occurrence of the larvae in the human alimentary tract may be 
accounted for in several ways. The flies may have deposited 
the eggs on the lips or in the nostrils of the patient, or the 
eggs may have been deposited on the food, subsequently 
