A nihyomyiidcB 



139 



4 P.M., with five grain doses of salol four times a day. The customary 

 parasiticides yielded no marked benefit. At the time of the report 

 the patient passed from four to fifty larvae per day, and was showiag 

 some signs of improvement. The nausea had disappeared, her 

 nervousness was less evident, and there was a slight gain in weight. 

 The case was comphcated by various other disorders, but the 

 symptoms given above seem to be in large part attributable to the 

 myasis. There is nothing in the case to justify the assumption 

 that larvce were continuously present, for years. It seems more 

 reasonable to suppose that something in the habits of the patient 

 favored repeated infestation. Nevertheless, a study of the various 

 cases of intestinal myasis caused by these and 

 other species of dipterous larvse seems to indi- 

 cate that the normal life cycle may be con- 

 siderably prolonged tmder the unusual conditions. 

 The best authenticated cases of myasis of the 

 urinary passage have been due to larvae of 

 Fannia. Chevril (1909) collected and described 

 twenty cases, of which seven seemed beyond 

 doubt. One of these was that of a woman of 

 fifty-five who stiff ered from albuminuria, and 

 urinated with much difficulty, and finally passed 

 thirty to forty larvae of Fannia canicularis. 



It is probable that infestation usually occurs 

 through eating partially decayed fruit or vege- 

 tables on which the files have deposited their 

 eggs. Wellman points out that the flies may 

 deposit their eggs in or about the anus of 

 persons using outside privies and Hewitt 

 believes that this latter method of infection is probably the common 

 one in the case of infants belonging to careless mothers. "Such 

 infants are sometimes left about in an exposed and not very clean 

 condition, in consequence of which flies are readily attracted to them 

 and deposit their eggs." 



Muscinae — The larvae of the common house-fly, Musca domestica, 

 are occasionally recorded as having been passed with the feces or 

 vomit of man. While such cases may occur, it is probable that in 

 most instances similar appearing larvae of other insects have been 

 mistakenly identified. 



Larva of Fannia 

 scalaris. 



