WINGS AND FLIGHT. 137 



that they offer no impediment to their home move- 

 ments, while the neatness of their packing is in itself 

 a security against damage. The queen of the bee- 

 hive, indeed, proverbially carries her wings very 

 closely set over the back [see Fig. 5), for the 

 greater length of her life demands the greater care ; 

 and so the gauzy membranes, in her case, are capable 

 of sustaining the wear of three or four years, yet re- 

 maining good enough for duty. 



Presently we shall discover that the rate of vibration 

 given to the wings during flight is prodigious, and then 

 the division, so valuable during repose, becomes an 

 impediment, for the air cannot be so efficiently beaten 

 by two narrow wings as by one of their united width. 

 And here, again, a device, charming in its" mechanical 

 simplicity and perfection, presents itself. The inner 

 margin (c, d, A, Fig. 27) of the anterior wing is folded 

 under, in a plait, while a series of minute blunt hooks 

 (e, f, B) are turned up upon the outer margin of the 

 under, or posterior one. As the anterior (upper) 

 wing moves outwards into position for flight, its 

 down-turned plait passes over the upper surface of 

 the lower wing, and is caught by the upturned 

 hooks, as C and D will make clear ; and now the 

 two wings, wedded into one, strike the air : but, at 

 the moment the flying insect settles, these, by falling 

 back into position, become immediately free, since the 

 plait simply sHps from the hooks, and the wings take 

 up their superposed position. 



The hooklets decrease in size in beautiful grada- 

 tion towards the wing point — the largest are about 

 ■jiy-in., the smallest, e^in. in length — but they are not 



