772 SUMMARY OF CURRENT RESEARCHES RELATING TO 



that what the bees hear are not the loud, low sounds, but the higher 

 overtones at the verge of or beyond our range of hearing. 



As regards the industry of wasps, he timed a bee and a wasp, for 

 each of which, he provided a store of honey, and he found that the 

 wasp began earlier in the morning, and worked on later in the day. 

 He did not, however, quote this as proving greater industry on the 

 part of the wasp, as it might be that they are less sensitive to cold. 

 Moreover, though the bee's proboscis is admirably adapted to extract 

 honey from tubular flowers, when the honey is exposed, as in this 

 case, the wasp appears able to swallow it more rapidly. This 

 particular wasp began work at four in the morning, and went on 

 without any rest or intermission till a quarter to eight in the evening, 

 during which time she paid 116 visits. 



Larvae and Pupae of Biptera.* — In continuation of a former 

 memoir,t Head-forester BeliDg describes the metamorphoses of 39 

 species of flies belonging to the families Tabaniclae, Leptidae, Asilidse, 

 Empidse, Dolichopidas and Syrphicke. He concludes by giving an 

 analytical table, occupying four pages, in which the characters of the 

 larvae of 21 genera are contrasted in accordance with the dichotomic 

 method. 



Organs of Flight in Hemiptera.J — L. Moleyre prefaces a state- 

 ment of the result of his observations by pointing out that in most 

 Hemiptera the part played by the anterior and posterior wings during 

 flight is almost equally important. But the former (hemielytra) are 

 usually horny, whilst the latter remain quite membranous. Each of 

 the two pairs of wings having a distinct structure and capacity, it is 

 indispensable that they should supplement one another and that 

 perfect solidarity should exist between them in their different move- 

 ments. The apparatus which serves to attach the wings to the hemi- 

 elytra consequently acquires, from a physiological point of view, 

 exceptional importance. Accordingly he has undertaken an examina- 

 tion of its conformation in the different groups of Hemiptera. 



In the Cicadidse the connecting apparatus is simplest. In them, 

 as well as in Fulgora and some allied genera, the posterior margin of 

 the hemielytron is folded underneath, starting from the middle, a deep 

 furrow being formed, in which, at the moment of flight, a correspond- 

 ing fold of the wing fits. In Fulgora the folded portion of the wing 

 begins to be differentiated. 



In the Membracidas, the Cercopidse, and the Iassidae, the fold is 

 reduced to a sort of plate inclined backwards on the plane of the 

 wing, often bent into a semicircle and furnished at the extremity with 

 fine serrations. 



In the sub-order Heteroptera, it is the fold of the hemielytra, and 

 not that of the wings, which is differentiated. There is also a con- 

 necting apparatus which is only found in certain families of Homoptera. 

 In the groups where it attains its greatest development, it appears to 



* Arch. f. Nttturgesch.. xlviii. (1882) pp. 187-240. 



t Ibid., xli. (1875). 



X Comptes Kendus, xcv. (1882) pp. 349-52. 



