6 2 Of Flies. 
their alvi, line the cells they perforate in the earth, fay 
their eggs therein, and then carry into them maggots 
from the leaves of trees, and feal them up clofe and 
neatly ; thefe walps have their jaws not only very ftrong, 
1but nicely fixed, curved, and fet for gnawing, and fcrap- 
ing. Thofe little holes they perforate in the earth and 
wood, as well as the feveral parts of the wafp kfelf, are 
a pleafant objebt for the microfcope. 
The bearers of fruit-trees are full of afperities, and 
not fo fmoot’n on their bark as the other parts of the tree 
are. If after harveft, and any time in winter, you view 
thefe bearers in the microfcope, their cavities will be 
found to be full of eggs, of an oblong figure, and citron 
colour, efpecially in thofe years wherein the caterpillars G 
have been numerous. Out of thefe they are hatched in 
the fpring. The feafons which ufually deftroy them, 
are fuch as come in with early hears, before the coming 
out of the buds and blofloms, and on which a nipping 
frofty air enfues, which foon kills them. 
Of oak cones. 
T HESE cones are, to appearance, perfectly like 
gems, only bigger, being nothing elfe than thefe 
increafed in bignefs, inftead of length. The caufe of this 
©bftruction in the vegetation is this; into the very heart 
of the young tender gem or bud, (which begins to be 
turgid in June, and to fhoot forwards the latter end of 
that month, and the beginning of the next) into this bud 
the parent infect thrufts one or more eggs, and perhaps 
not without fome venomous d ichon therewith; this egg 
foon becomes a maggot, and eats itfelf a little ceil in 
the 
c Phil. Tranf, Nc^ 237, 4 Phy, Theo. p, 397. 
