A Burrowing Wasp. 



421 



investigators have found the beginnings of sexual organs by dissection — and tlie 

 generative system has got to be built up. So with other systems — the Insect has 

 largely to be made up afresh from the materials of the caterpillar. Even the 

 scales which clothe and give pattern and colour to the wings have all to be developed. 

 The number of scales on all the wings of one of the large South American morphos 

 has been computed at a million and a half. They are flattened bags containing 

 fluid or air, and are of a similar nature to hairs, into which indeed they gradually 

 merge. It is these scales which give colour and pattern to the butterfly, sometimes 

 by a true pigment inside the scale w^hich shows through, sometimes by an optical 

 effect produced by the microscopic ridges and grooves on the surface of the scale. 

 Each of these scales is attached to the wing bv a footstalk, which fits into a receptacle 

 excavated in the wing-membrane, 

 one row^ of scales overlapping the 

 footstalks of the next row, a 

 manner which may be said to be 

 copied in the tiling of a roof. In 

 addition to the scales which cover 

 the greater part of the wings in 

 both sexes, there are special long 

 slender scales (termed andro- 

 conia) w^hich are peculiar to the 

 wings of the males, and these are 

 believed to cover glands which are 

 the source of scents produced for 

 the purpose of charming the 

 females. It has been proved by 

 experiment that various butter- 

 flies have their own distinctive 

 odours, which are either stronger 

 in or restricted to the males. 



The antennae of a caterpillar 

 are very small and inconspicuous 

 organs ; in the butterflv they are 



developed to great length , and The largo rhinoccros-beetle of the continent "phovvn with the groat hairy wasp 

 ^ O D ' whose mission IS to keep down the numbers of the beetle. The beetle is coloured 



either have their free ends clubbed a|uniform brown. Both insects arc shown of the natural size. 



or they are thickened a little short of the tip. Another remarkable development 

 of the perfect butterflv is the proboscis, which is always of great length. It is kept 

 coiled in a flat spiral close to the head ; but when the butterfly \'isits flowers it is 

 unrolled, the tip is inserted in the nectar of the flower, and the sweet juices are sucked 

 up it. This proboscis reall\- consists of two tubes, each with a concave inner face, 

 and these faces so interlock b\- their edges that they form a third or central tube. 



A Burrowing Wasp. 



^^'e have alreadv given some account of wasps and bees that bore shafts into 

 the ground, terminating in nest-cells to whicli tluA- bring their jnTy in order that it 



;/■:. su-[y, F.L.s. 

 Khinoceros- Beetle and its Foe. 



