358 MOTIONS OF INSECTS. 



of any bird. — The aerial iiiovements of the hive-bee 

 are more direct and leisurely. When leaving the hive 

 for an excursion, I have observed that as soon as they 

 come out they turn about as if to survey the entrance, 

 and then wheeling- round in a circle, fly off. When 

 they return to the hive, they often fly from side to side, 

 as if to examine before they alight. When swarming, 

 the heads of all are turned towards the group at the 

 mouth of their dwelling ; and upon rising into the 

 air these little creatures fly so thick in every direction, 

 as to appear like a kind of net-work with meshes of 

 every angle. The queen also, upon going forth, when 

 her object is to pair, after returning to reconnoitre, be- 

 gins her flight by describing circles of conatderable di- 

 ameter, thus rising spirally with a rapid motion*. The 

 object of these gyrations is probably to increase her 

 chance of meeting with a drone. — I have not much to 

 tell you with respect to the flight of other insects of 

 this order, except that a spider-wasp (Pompilus viati' 

 cus, F.), whose sting is redoubtable, and which often, 

 when we are in the vicinity of sandy sunny banks, ac- 

 companies our steps, has a kind of jumping movement 

 when it flies. 



The next order, the Diptera, consists altogether of 

 two-winged flies : — but to replace the under wings of 

 the tetrapterous insects, they are furnished with poisers, 

 and numbers of them also with winglets. The poisers 

 (Halteres) are little membranaceous threads placed 

 one under the origin of each wing, near a spiracle, and 

 terminated by an oval, round, or triangular button, 

 which seems capable of dilatation and contraction. 



•Iluber, i. 38. 



