mo Mr . Marshall's Account of 
black fpecki outwardly fringed with hair ; but which, opening 
longitudinally, appears to be the end of a cafe, containing a 
delicate point or fling (about one* twentieth of an inch in 
length) which on a curfory view appears to be a fimple lan- 
ceolated inftrument, with a ft roc g line palling down the mid- 
dle, and ferrated at its edges ; but, on a clofer inf pe&i m, and 
by agitating it ftrongly with the point of a needle, it leparates 
into three one-edged inftruments, hanger-like as to their gene- 
ral form, with a fpiral lme or wrinkle winding from the point 
to the bafe, making ten or twelve revolutions, which line, 
palling over their edges, gives them fome appearance of being 
ferrated. 
By the help of thefe inftruments, I apprehend, the female 
depolits her eggs in the edge of the turnip-leaf (or fometimes, 
perhaps, in the nerves or ribs on the under iurface of the 
leaf) ; thus far I can fay, and I think with a confiderable de- 
gree of certainty, that having put lome frefh turnip leaves into a 
glafs containing feveral of the male and female flies, I perceived 
(by the means of a fimple magnifier) that one of the females, 
after examining attentively the edge of the leaf, and finding a 
part which appeared to me to have been bitten, unfheathed her 
inftruments, infinuated them into the edge of the leaf, and 
having forced them afunder fo as to open a pipe or channel 
between them, placed her pubes (the fituation of which from 
repeated and almoft inceiftant copulations 1 had been able to afeer- 
tain precifely, and to the lower part of which thefe inftruments 
feem to be fixed) to the orifice, and having remained a few 
feconds in that pofture, deliberately drew out the inftruments 
(which the tranfparency of the leaf held againft a ftrong light 
afforded me an opportunity of feting very plainly) and pro- 
ceeded to fearch for another convenient place tor her purpofe. 
The 
