Chrysomyia macellaria 



141 



but is especially abundant in the south. While the larvae breed in 

 decaying matter in general, they so commonly breed in the living 

 flesh of animals that they merit rank as true parasites. The females 

 are attracted to open wounds of all kinds on cattle and other animals 

 and quickly deposit large numbers of eggs. Animals which have 

 been recently castrated, dehorned, or branded, injured by barbed 

 wire, or even by the attacks of ticks are promptly attacked in the 

 regions where the fly abounds. Even the navel of yoimg calves or 

 discharges from the vulva of cows may attract the insect. 



Not infrequently the fly attacks man, being attracted by an of- 

 fensive breath, a chronic catarrh, or a purulent discharge from the 

 ears. Most common are the cases where the eggs are deposited in 



C B A 



104. Calliphora erythrocephala, (x6). After Graham-Smith. 



the nostrils. The larvae, which are hatched in a day or two, are 

 provided with strong spines and proceed to bore into the tissues 

 of the nose, even down into or through the bone, into the frontal 

 sinus, the pharynx, larynx, and neighboring parts. 



Osbom (1896) quotes a number of detailed accounts of the attacks 

 of the Chrysomyia on man. A vivid picture of the symptomology 

 of rhinal myasis caused by the larvae of this fly is given by Castellani 

 and Chalmers: "Some couple of days after a person suffering from 

 a chronic catarrh, foul breath, or ozffina, has slept in the open or has 

 been attacked by a fly when riding or driving, — i.e., when the hands 

 are engaged — signs of severe catarrh appear, accompanied with 

 inordinate sneezing and severe pain over the root of the nose or the 

 frontal bone. Quickly the nose becomes swollen, and later the face 

 also may swell, while examination of the nose may show the presence 



