162 SUMMARY OF CURRENT RESEARCHES RELATING TO 



II. Bees living socially : 



9. The fertilised female hibernates alone ; forms, in spring, 



a new nest ; is helped by a brood of workers which 

 are only parthenogenetically reproductive in isolated 

 cases ; and produces in the course of the summer 

 males and females. In autumn the whole society 

 dies off except the fertilised females : humble-bees. 



10. Permanent societies, with imperfect combs : the 



tropical species of Melipona and Trigona. 



11. Permanent societies, with perfect combs : Apis mel- 



lifica, A. dorsata, A.florea. 



Among the humble-bees, some (in the north) are quite solitary (females 

 and males, without workers) ; some (e.g. in Germany) form summer- 

 societies ; some (e.g. in Corsica and the Balearic Islands) partially survive 

 the winter as societies ; and, finally, some tropical forms (according to 

 R. v. Jhering) are permanently social, with many females. The parti- 

 cular kind of honeycomb characteristic of Apis remains quite apart from 

 the other forms. 



Genus Simulium.* — E. Roubaud finds that the genus SimuUum 

 Latreille may be conveniently divided into two new sub-genera — Pro- 

 Simulium and Eu-Simulium — which differ as regards the second joint of 

 the posterior tarsi, the pupal cases, and the nymphal filaments. 



Undescribed Organ in Thorax of Winged Ants.f — Charles Janet 

 describes a mesonotal and a metanotal diaphragm in males and females 

 of Lasius niger, which bring about a certain displacement of the blood 

 during the resting periods of the wing-muscles, or after their dis- 

 appearance. 



Stalked Eggs of Cynips tozae and Synergus reinhardi. J — E. Bugnion 

 describes the stalked egg of Cynips toz(e, and also that of Synergus 

 reinhardi, which is commensal with Cynips Tcollari. In Synergus the 

 stalk has a length of 1 •004 mm., more than five times the length of the 

 egg (0* 197 mm.). Males were observed, but the fertilisation is difficult 

 to explain, for the egg-envelope is thick, and there is no micropyle. 



Pachylomma cremieri and Lasius fuliginosus.§ — Ruggero Cobelli 

 finds that when the ants {Lasius) transport their larvse from the 

 summer nest on the willow-tree to the subterranean winter nest at the 

 foot of the tree, the rare parasite Pachylomma cremieri de Romand 

 inserts its eggs on the ant-larv£e. The parasitic eggs are thus taken 

 with the larvffi to the hibernation quarters, and it is probable that the 

 metamorphosis of the Pachylomma is completed when the ant-larvse are 

 again removed in spring to the willow-tree. 



Insects in Amber.|| — F. Meunier gives an account of the Tipulidae 

 and Dixidse found in Baltic amber. No fewer than eighteen genera are 



* Comptes Rendus, cxliii. (1906) pp. 519-21. 



t Tom. cit., pp. 522-3 (1 fig.). 



X Bull. Soc. Vaudoise Sci. Nat., xlii. (1906) pp. 185-96 (8 figs.). 



§ Verb. k.k. Zool. Bot. Ges. Wien, Ivi. (1906) pp. 475-7. 



II Ana. Sci. Nat. (Zool.) iv. (1906) pp. 349-401 (5 pis.). 



