THE BLOW-FLY. 157 
All blow-flies can become the authors of epidemics. Dr. 
Maddox read a paper before the Royal Microscopical Society, 
in which he detailed the results of experiments especially 
about the relations between the common-fly and the comma 
bacillus. According to the Scientific American the results of 
all his investigations lead him to believe that the comma 
bacillus from cultures can pass in a living state through the 
digestive tubes of some insects, and through this fact, that 
such insects are likely to become an important means of dis- 
tributing disease, especially to animals that feed upon them. 
This is in accordance with the views of Dr. Grossi, that ‘“in- 
sects, especially flies, may be considered as veritable authors 
of epidemics and agents in infectious maladies.” 
As these flies deposit their eggs on open sores or upon 
wet, filthy parts of the skin, serious trouble may be caused. 
To prevent this all wet and filthy hair should be cut and the 
wounds should be kept clean and rendered antiseptic. A 
good lotion for this purpose is made by mixing one part of 
earbolic acid with fifty parts of water; or a mixture should 
be made of one ounce oil of tar and twenty ounces of sweet-oil. 
It is stated from time to time that maggots have been 
vomited from the human stomach. Such maggots are the 
young of blow-tlies or of other similar flies which may have 
been swallowed in some way, and as they can exist for some 
time in the stomach and intestines they can cause serious 
trouble. The mysterious fly-disease (J/yiasis) is caused by 
the presence of such maggots in the interior of human beings. 
The maggots of Sarcophaga latifrons have repeatedly 
been removed from ulcers in the ear, and other cases have 
been reported where such maggots had destroyed vision by 
penetrating to the eye. 
About the very worst of such flesh- or blow-flies is the 
Texas screw-worm, an insect that has a very bad reputation, 
and what is worse, one that is well-earned. As this insect is 
also found in Minnesota, and has already done some harm, 
it is best to describe it more in detail. 
