EGGS, &c. OF ANTs. 71 
of extension; but why is it that those 
egos, which nature has enclosed, in a 
flexible membrane, do not increase ? 
The envelope of the egg may, in this in- 
stance, be compared to the membrane 
which includes the human foetus, and 
those of quadrupeds. 
Nature has formed the eggs of some 
other insects in such a manner, that they 
are also capable of increase: such are, 
according to M. Vallisnieri, the eggs of 
the Tenthredo, which produce those 
larvee that feed upon the rose. * 
These remarkable examples authorise 
me in admitting an increase in size, in 
the eggs of ants, as fully proved; although 
it may not be exactly under the same 
circumstances as those of which the philo- 
sopher I have just quoted speaks ; but 
if they are not surrounded with a liquid, 
or preserved from the influence of the 
external air, their pellicle, moistened every 
instant by the workers, may preserve a 
* Latreille alludes to this increase in the size of 
the eggs, both in these insects, and the Cynips. —T. 
