88 STATES OF INSECTS. (Lgg.) 
egg is first laid, nothing indeed is to be seen in it but the 
fluid just mentioned ; the first change in this fluid is the 
appearance of the head of the embryo, more particularly 
in Coleoptera, of two points, the rudiments of the mandi- 
bles, and of those apertures into the tracheee which I 
have called spiracles? ; the little animal we may suppose 
then assumes its form and limbs. The embryo is usually 
so folded in the egg that the head and tail meet”, and 
the head, annuli, and other parts of the larva are often 
visible through the shell‘. Swammerdam even saw the 
pulsation of the great dorsal vessel through the shell of 
the egg of Oryctes nasicornis. 
Under this head I must notice another singular cir- 
cumstance peculiar I believe to the eggs of insects, that 
‘sometimes, though rarely, they are covered with down or 
hair. Those of a singular little hemipterous insect, of a 
genus I believe at present undescribed, the ravages of 
which upon the larch have been before noticed‘, are 
coyered by a downy web, as is the case with the ani- 
mal itself. De Geer has described the eggs of a bug, 
not uncommon in this country (Pentatoma juniperina), 
which are reticulated with black veins, in which very 
short bristles are planted*. I possess also a nest of 
brown eggs, probably of a species of the same genus, 
found upon furze, which appear to be covered with very 
short downy hairs. ‘The top of these is flat, and sur- 
the Amnios immediately envelops the foetus, the pellicle seems most 
analogous to it, and the shell to the Chorion. 
* Swamm. Bidl, Nat. ed. Hill. 1. 133.a. Comp. N. Dict. d’ Hist. 
Nat. xvi. 246. 
> Swamm. Ibid. © Sepp. ayes llapeere. Vee. 1V. fe. 
* See above, Vou. I. p. 211: it is there called an Aphis, but it is a 
distinet genus. De Geer iit, 245, ¢, xiii. f. 20—22. 
