rilE rOLISTES GALLICA. 239 



took the precaution to mark, in eacli of the nests experimented 

 upon, the occupied and empty ceHs. 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 

 larv£E, which prospered under the care of the virgin society. All 

 these larvce, at their final transformation, fnrnisJied males, in oppo- 

 tion to the larvee which had been previously prodiiced 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 lilieieea) 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. 2S. 



