THE POLISTES GALLIC A. 
239 
took the precaution to mark, in each of the nests experimented 
upon, the occupied and empty cells. In a few days he perceived 
that some of the latter contained eggs. Careful examination even 
enabled him to surprise some of the little virgin wasps at the moment 
when they were depositing their eggs at the bottom of a cell. 
These individuals were at once sacrificed and examined. There 
were eggs within them in abundance, but no evidences of fertilisa- 
tion by the male. During this time, thanks to the assiduous care 
of the young virgins, new female individuals — produced from the 
large larvae which had not been sacrificed — arrived at their com- 
plete development, and at once took part in the labours of the 
society. The nests were consequently enlarged by new cells, 
which were speedily occupied by eggs laid by the virgins. All 
these eggs — and this is an important fact — were developed not- 
withstanding the absence of fecundation, and gave birth to young 
larvae, which prospered under the care of the virgin society. All 
these larvce , at their final transformation , furnished males , in oppo- 
tion to the larvae which had been previously produced by the 
original mother, and which had furnished females only. It is 
therefore evident that in Polistes gallica the male individuals 
originate by parthenogenesis, from unfecundated eggs.* 
There are some other wasps, which have very slim bodies, 
that constitute the genus Polybia. They are not known in Europe, 
but are very common in tropical America, where they form either 
enormous nests or tiny and beautifully-formed habitations. One 
of the species ( Polybia liliacea ) makes a most wonderful nest, 
which is often nearly four feet in height, and which contains 
thousands of cells. It is attached to branches of trees, and its 
covering, which is almost like cardboard, is rough, and is even 
attached to the internal combs. Mr. White described a huge 
Polybia nest from Central America, and noticed that its very 
thick envelope was covered with large pointed tubercles. On the 
other hand, some of the small species make their nests on the 
lower surface of leaves, and one which is here represented, is 
common in Guatemala. 
Polybia palmarum is a very small wasp, about a quarter of an 
* “ Ann. and Mag. Nat. Hist.,” vol. v., No. 28. 
