SOCIAL WASPS AND HORNTAILS 85 



of the abdomen is produced above into a long and stout 

 spine, which is nearly half as long as the free part of 

 the ovipositor. With the ovipositor the mother pierces 

 the bark of the tree she has chosen for the support of 

 her progeny, in order that she may deposit her eggs 

 in such positions as shall place the young grubs in 

 circumstances of comfort and opulence from the moment 

 they first see the light. 



Her consort is altogether a slenderer smaller insect, 

 and has a reddish body, without the mourning band 

 and, of course, without the formidable boring apparatus ; 

 all he can show in the way of offensive or defensive 

 weapons is a very sharp point at the end of the last 

 segment of his abdomen, in the same position as the 

 much larger spine of his spouse. 



Sirex gifjas is sufficiently large to show with tolerable 

 ease a certain structure in the wings which is eminently 

 characteristic of the Hymenoptera, though often too 

 small to be readily seen. When spread out, the fore 

 and hind wing on each side will be found to be in 

 some mysterious way connected, so as to move in con- 

 cert, and to offer, over the greater part of their area, 

 one unbroken resisting surface to the air. If, however, 

 they are waved about in various directions, they may 

 at length be caused to spring apart, and then, if the 

 front edge of the hind wing be held towards the light, 

 the explanation of the mysterious union will be found. 

 Here will be seen, running part of the way along the 

 margin, a row of between fifty and sixty tiny hooks, 

 bent upwards and backwards in such a way that when 

 the wing is brought into position behind its fellow 

 they clasp from underneath the stout nervure which 

 bounds the forewing on its hinder edge, and thus hook 

 the two wings together. In the centre they are placed 



