SARCOPHAGIDÆ--The larvæ (fig. 105) of flies of this family usually feed upon meats, but have been found in cheese, oleomargerine, pickled herring, dead and living insects, cow dung and human feces. Certain species are parasitic in insects. Higgins (1890) reported an instance of "hundreds" of larvæ of _Sarcophaga_ being vomited by a child eighteen months of age. There was no doubt as to their origin for they were voided while the physician was in the room. There are many other reports of their occurrence in the alimentary canal. We have recorded elsewhere (Riley, 1906) a case in which some ten or twelve larvæ of _Sarcophaga_ were found feeding on the diseased tissues of a malignant tumor. The tumor, a melanotic sarcoma, was about the size of a small walnut, and located in the small of the back of an elderly lady. Although they had irritated and caused a slight hæmorrhage, neither the patient nor others of the family knew of their presence. Any discomfort which they had caused had been attributed to the sarcomatous growth. The infestation occurred in mid-summer. It is probable that the adult was attracted by the odor of the discharges and deposited the living maggots upon the diseased tissues. [Illustration: 106. A flesh fly (Sarcophaga), (×4). After Graham-Smith.] According to Küchenmeister, _Sarcophaga carnaria_ (fig. 106), attracted by the odor, deposits its eggs and larvæ in the vagina of girls and women when they lie naked in hot summer days upon dirty clothes, or when they have a discharge from the vagina. In malignant inflammations of the eyes the larvæ even nestle under the eyelids and in Egypt, for example, produce a very serious addition to the effects of small-pox upon the cornea, as according to Pruner, in such cases perforation of the cornea usually takes place. [Illustration: 107. Chrysomyia macellaria, (×3).] _Wohlfartia magnifica_ is another Sarcophagid which commonly infests man in the regions where it is abundant. It is found in all Europe but is especially common in Russia, where Portschinsky has devoted much attention to its ravages. It deposits living larvæ in wounds, the nasal fossæ, the ears and the eyes, causing injuries even more revolting than those described for _Chrysomyia_. CHAPTER V ARTHROPODS AS SIMPLE CARRIERS OF DISEASE The fact that certain arthropods are poisonous, or may affect the health of man as direct parasites has always received attention in the medical literature. We come now to the more modern aspect of our subject,--the consideration of insects and other arthropods as transmitters and disseminators of disease.