Dipterous Larvce in Human Excreta. 55 
GROUP D. 
Animals which concern Man as causing bodily injury, some- 
times death, to him, and in other cases disease, often of 
a deadly character. 
Live Dipterous Larvae in Human Excreta and 
Notes on Species producing Myiasis. 
Mr. J. W. Bridge, of the University, Birmingham, sent two larvae 
from the excreta of a woman with the following letter, dated 
Dec. 4th, 1901 : — 
I ask you to identify the specimens which I am sending here- 
with. They were sent to me by a doctor at Shrewsbury who states that 
they were passed per rectum by a patient suffering from cancer. If you 
can give me any clue to their identification I shall be grateful. 
To this the following reply was sent : — 
The larvae you send from the excreta of the woman suffering 
from cancer are those of one of the Anthomyiidae and of the genus 
Homalomyia. Certain species of these diptera are responsible for authentic 
cases of internal Myiasis. They are taken in with vegetable food and 
retain their vitality and are sometimes passed in the fmces alive. They are 
in no way connected with cancer. 
Most of the cases of human Myiasis are due to the larvae 
of Compsomyia, Calliphora, Sarcophila,, Homcdomyict, Ochromyia, 
Dermatobia and Auchmeroyia. Myiasis may be either (i) cutaneous 
or (ii) internal. 
Homalomyia canicularis, Linn., has been reported by Hagen 
(Proc. Bost. Soc., N.H. xx. 107) as living in the larval stage in the 
urethra of a patient. Probably, says ISTuttall, a case of pseudo- 
parasitism. 
The following other dipterous larvae have been known to cause 
external or cutaneous myiasis. 
Sarcophila magnified, Schiner, which deposits its eggs in wounds 
on man and animals. 
