84 STATES OF INSECTS. (Zgg. 
tion of the latter it may be observed, that the species of 
the genus Hydrachna usually attach their eggs to the 
body and legs of aquatic insects, as for instance H. 
abstergens to the water-scorpion (Nepa cinerea), &c.* 
2. After having thus laid before you some of the pro- 
cedures of those insects that usually deposit their eggs 
in groups, either naked or defended by coverings of va- 
rious kinds, I next proceed to a rapid survey of those of 
the species that commonly deposit them singly. Some 
of these, as for instance the Admiral Butterfly (Vanessa 
Atalanta), glue each egg carefully to its destined leaf by 
alighting on it fora moment. Another butterfly (Aizp- 
parchia Hyperanthus) whose caterpillar is polyphagous, 
drops hers at random on different plants. In general it 
may be observed, that all those larvae which live in so- 
litude, as in the interior of wood, leaves, fruits, grain, 
animals, &c., proceed from eggs laid singly by the fe- 
male, which is usually provided with an appropriate 
instrument for depositing them in their proper situa- 
tion. Thus the nut-weevil (Balaninus Nucum) and also 
that of the acorn (B. Glandium) pierce a nut or an acorn 
with their long beak, and then deposit in the hole an 
egg, from which proceeds the maggot that destroys those 
fruits. Leeuwenhoek asserts that the common weevil 
(Calandra granaria) adopts the same process, boring a 
hole in every single grain of corn before it commits an 
egg to it, and at the same time, by this manceuvre, pre- 
pares a smal] quantity of flour to serve for the food of 
the tender grub when it is first hatched”. It is probable 
that the Rhyncophorous or weevil tribe in general chiefly 
* N. Dict. d’ Hist. Nat. xv. 445. Ros. iii. 156. > Epist. 1687. 
