MOTIONS OF INSECTS. 357 
the wings are usually proportioned to the weight of the 
insect. Thus the saw-flies have generally bodies thicker 
than those of most other Hymenoptera, while those that 
have fewer nervures are more slender. This, however, 
does not hold good in all cases—so that the dimensions 
and cut of the wings, the strength of their nervures, and 
the force of their muscles, must also be taken into con- 
sideration. The wings of many of these insects when 
expanded, are kept in the same plane by means of small 
hooks (Hamidi) in the anterior margin of the under 
wing, which lay hold of the posterior margin of the 
upper*. Another peculiarity also distinguishes them. 
Base covers (Tegule), or small concavo-convex shields, 
protect the base of the wings from injury>, or displace- 
ment. 
The most powerful fliers in this order are the humble- 
bees, which, like the dung-chafers (Geotrupes), traverse 
the air in segments of a circle, the arc of which is alter- 
nately to right and left. The rapidity of their flight is 
so great, that could it be calculated, it would be found, 
the size of the creature considered, far to exceed that of 
any bird.—The aérial movements of the hive-bee are 
more direct and leisurely. When leaving the hive for 
an excursion, I have observed that as scon 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 ex- 
amine 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 crea- 
4 Kirby, Mon. Ap. Angi. i. 96. 108. ft. xi. fi 19. 
4 Ibid. 96. 107. £. v. f..8. dd. 
