616 DIPTEEA. 



sporting together, in large swarms, in the air, like certain 

 kinds of gnats. In the larva state some of them live in 

 manure, and in rotten vegetable substances ; others are 

 found in the roots of living plants, such as onions, radishes, 

 turnips, and even in the pulpy parts of leaves and of stems, 

 which they devour. The latter have nearly the same form 

 as the maggots of common flies ; some of the former are 

 shorter, flattened, and fringed on the sides with feathery 

 hairs. 



Many instances are recorded of these fringed maggots 

 having been discharged from the human body. They are 

 supposed to be the young of a fly named Aathomyia QHoma- 

 Jomyia) scalaris* Flies closely resembling this are some- 

 times seen in privies, and a friend has presented me with 

 one of them, together with the dried larva-skin out of which 

 it came. The larva was found in excrement. The fly is 

 grayish black, and hairy, with large copper-colored eyes, 

 which are surrounded by a narrow silvery white line. It 

 measures one quarter of an inch in length. The larva-skin 

 has two rows of hairs on the back, and two more on each 

 side. Another fly, sometimes seen on windows in the au- 

 tumn, is produced, if I mistake not. from a hairy maggot 

 that lives in rotten turnips. This fly strikingly resembles 

 the Anthomyia canicularis of Europe, and is possibly iden- 

 tical with it. It is of a dark gray color, with copper-colored 

 eyes, encircled by a silvery white line, and with a large, 

 semitransparent, yellowish spot on each side of the first three 

 rings of the hind body. It measures rather less than one 

 quarter of an inch in length. The fringed maggots of the 

 canicularis are stated by some naturalists to have been ob- 

 tained from the human body. It is not impossible that they 

 may have been swallowed with turnips, or other vegetables, 

 eaten when gomg to decay. 



Radishes, while growing, are very apt to be attacked by 



* For an account of the transformations of the fly of privies, with figures, see 

 Swaramerdam's "Book of Nature." translated by Hill, Part II. p. 3S, plate 38. 



