616 
DIPT ERA. 
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 arc recorded of these fringed maggots 
having been discharged from the human body. They are 
supposed to be the young of a fly named Anthomyia ( 'Soma - 
lomyia) 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 going 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 
Swammerdam’s “ Book of Nature,” translated by Hill, Fart II. p. 38 , plate 38 . 
