306 SUMMARY OF CUKRENT RESEARCHES RELATING TO 



municates many interesting facts concerning the habits and structure of 

 these bees. A comparison of representatives of the genera Melipona 

 and Trigona with Apis m&llifka shows, r iin addition to the characters 

 common to all Apidse, such as the existence of drones, queens and 

 workers, swarming, collection of honey and pollen, and the use of wax 

 for building, two important structural differences, viz. the rudimentary 

 nature of the sting, and the formation of the wax-plates on the dorsal 

 side of the abdomen. These differences have led the author to con- 

 stitute the genera in question a separate family from the Apiche. These 

 bees build their nests mostly in the stems or branches of trees ; they 

 choose trees that rot easiest ; but some build in the earth, as deep as 

 four metres, with a perpendicular, slanting or spirally twisted tube to 

 the surface. The nests and the structural peculiarities are well illus- 

 trated in the plates. 



Notes on Ants.* — Adele M. Fielde gives supplementary notes of 

 experiments designed to ascertain whether any of the rays of light to 

 which the ants are exposed in seeking food, so affect their metabolism 

 as to produce that difference of odour, which, as a result of previous 

 experiments, she believes is the cause of hostility between colonies of the 

 same species and variety, and which is co-incident with difference of 

 age in the individuals composing the colony. Incidentally it was found 

 that while at first they instinctively sought shelter from the ultra-violet 

 rays, after ten months' exposure to these, while still sensitive to them, 

 the ants appeared to have learned that they were innocuous and adjusted 

 their behaviour accordingly. On the main quest, however, the results 

 were negative. 



Myrmecological Notes. t — Auguste Forel contributes a miscellaneous 

 series of notes on ants. He submits facts which point to a hitherto 

 unheard-of occurrence, — a spontaneous slave-capturing, pillaging ex- 

 pedition undertaken by Strong ylognathus christophi v. rehbinderi. He 

 Teports on ants from Kairouan in Tunisia, from Biskra, from Jerusalem, 

 Cashmir, Brazil, and elsewhere, and on Gamponotas universitatis sp. n., 

 from near Geneva. 



Oviposition in Bombyx mori.ij: — Jules Gal points out that the 

 silk- moth lays eggs whether inseminated or not. But while females 

 which have had complete copulation lay their eggs quickly, those 

 which are virgin or which have had their copulation interrupted retain 

 their ova longer. Moreover, while the inseminated females live on 

 an average 1) • 3 days after oviposition, the ' virgins ' live for 11 • :> days 

 thereafter. 



Wings of Beetles.§ — W. L. Tower has made a careful investigation 

 of the origin and development of the wings of Coleoptera. He de- 

 scribes the wing primordium, the formation of the larval wings and the 

 tracheal system of the wings. The chief conclusion arrived at is, that 



* Proc. Acad. Nat. Sci. Philadelphia, lv. (1903) pp. 491-5. 



t Revue Suisse Zool., xii. (1904) pp. 1-52 (1 fig.). 



t Couiptes Rendus, cxxxvii. (1903) pp. 932-4. 



§ Zoo/. Jahrb., xvii. (1903) pp. 517-72 (7 pis. and 8 figs.). 



