Of Flies. 61 
langiam, and carry them to their nefts, after which they 
befmear them, and by incubation produce their own 
fpecies out of them. 
There is alfo a certain black and curious fly, whicjj 
proceeds from the gouty excrefcencies of the briar {talk % 
with red legs. Black, fmooth jointed antennae, large 
thorax, and belly in the lhape of an heart. It leaps like 
a flea. • 
The excrefcencies of the roots of cabbages, turneps* 
and divers other plants, have always a maggot in them, 
not yet fufficiently obferved. 
Caterpillars, and divers others infects, can emit threads 
or webs for their ufe. In this their nymph flate, they 
fecure themfelves from falling, by letting themfelves 
down from the boughs of trees, and other high places, 
with one of thefe threads, and fecure themfelves in their 
aurelia ftate, in cafes of their own weaving. 
Some of the fly tribe are alfo endowed with this tex- 
trine art, of thefe one fort fpins a long milk white Aiken 
web as big as the top of one’s finger, woven round bent 
ftalks of ribwort, &c. in meadows. The other is a lump 
of many yellow filken cafes flicking confufedly together 
on pofts, under coleworts, &c. thefe webs contain in 
them fmall whitifh maggots, which turn to a fmail black 
ichneumon fly, with long capillary antennae, tan-colour’d 
legs, long wdngs, reaching beyond their body with a 
black fpot near the middle, the alvus like an heart, and 
in fome a fmall fetaceous tail. Some of thefe flies are of 
a beautiful fhining green colour. The flies coming from 
thefe tw r o productions are nearly alike. 
Many of the ichneumon wafps b are remarkable for 
the nidification and provifion of their young. Thole 
which commonly have golden and black rings round 
their 
* fhy. Theo. p, 550, h Ibid, p. 228, 
