26 THE WINGS OF INSECTS. 



the upper part of a scale and the lower part of a feather : 

 the number of these is great, Leeuwenhoek counted 

 400,000 on the wings of the silk-worm moth,* and 

 this number must be less than that of other insects, hav- 

 ing larger wings. The shape and figure of these scales 

 are various, De Geer and Reaumur have given figures 

 of fifty six different kinds,t the annexed cuts represent 

 the magnifi'ed appearance of ♦ 



No. 1. Scales from the wings of the Yellow under-wing. 2. 

 Ghost moth. 3. Buff tip. i. Puss moth. 5. Drinker moth. 6. 

 Great white butterfly. 7. Green-veined butterfly. 8. Death^s head 

 hawk moth. 



The scales are sometimes arranojed on the winces 

 without order, but in most instances they are in trans- 

 verse lines, though not always rectilinear, they lie over 

 one another like slates on the roof of a house, and are in 

 position usually flat on the wing. Different coloured 

 hairs are sometimes planted among the scales or else 

 they replace them altogether. 



Butterflies fly in a zig zag line, making vertical 

 angles, and each zig zag is made up of smaller ones : 

 it is probable that this sort of motion renders it 

 difficult for birds to catch them in the air ; some sorts 

 fly with great rapidity, not, however, equal to that of 



* Hoole's Leeuwenhoek, i. 63. f De Geer, i. t. iii. f. 28. 



