Dipterous Larva 
i37 
//. Slits of the posterior stigmata sinuous or bent. Subfamily Muscinae. 
g. Slits of the posterior stigmata bent; usually two mouth hooks. Muscina 
stabulans (fig. 171, /), Muscina similis, Myiospila meditatunda (fig. 172, i), 
and some of the higher Anthomyiidce. 
gg. Slits of the posterior stigmata sinuous; mouth hooks usually consolidated 
into one. The house-fly ( Musca domestica fig. 171, d), the stable fly 
(Stomoxys calcitrans) the horn fly ( Lyperosia irritans), Pyrellia, Psendo- 
pyrellia, Morellia, Mesembrina. Polietes, et. al. (fig. 172 in part). 
Eristalis — The larvse of Eristalis are the so-called rat-tailed mag¬ 
gots, which develop in foul water. In a few instances these larvae 
have been known to pass through the human alimentary canal 
uninjured. Hall and Muir (1913) report the case of a boy five years 
of age, who had been ailing for ten weeks and who was under treat¬ 
ment for indigestion and chronic constipation. For some time he 
had vomited everything he ate. On administration of a vermifuge 
he voided one of the rat-tailed maggots of Eristalis. He admitted 
having drunk water from a ditch full of all manner of rotting matter. 
It was doubtless through this that he became infested. It is worth 
noting that the above described symptoms may have been due to 
other organisms or substances in the filthy water. 
Piophila casei, the cheese-fly (fig. 99), deposits its eggs not only 
in old cheeses, but on ham, bacon, and other fats. The larvae (fig. 98) 
are the well-known cheese skippers, which sometimes occur in great 
abundance on certain kinds of cheese. Indeed, some people have 
a comfortable theory that such infested cheese is especially good. 
Such being the case, it is small wonder that this species has been 
repeatedly reported as causing intestinal myasis. Thebault (1901) 
describes the case of a girl who, shortly after consuming a large piece 
of badly infested cheese, became ill and experienced severe pains 
in the region of the navel. Later these extended through the entire 
alimentary canal, the excrement was mixed with blood and she 
suffered from vertigo and severe headaches. During the four fol¬ 
lowing days the girl felt no change, although the excretion of the blood 
gradually diminished and stopped. On the fourth day she voided 
two half-digested larvae and, later, seven or eight, of which two were 
alive and moving. 
That these symptoms may be directly attributed to the larvae, 
or “skippers,”has been abundantly shown by experimental evidence. 
Portschinsky cites the case of a dog fed on cheese containing the 
larvae. The animal suffered much pain and its excrement contained 
blood. On post mortem it was found that the small intestine through- 
