MANUAL OF NATURAL HISTORY. 221 



duced by one species we are indebted for our ink, 

 that most important fluid in the history of learning 

 and civilization. Here also we find the Ichneumon- 

 Flies, which deposit their eggs in the bodies of other 

 insects, and which are eventually devoured by the 

 parasites. In tropical countries, species of Sphegidw 

 will be observed, forming nests in the corners of the 

 rooms, composed of several earth-cells, in each of 

 which the mother Pelopceus deposits a green cater- 

 pillar. The Velvet- Ants are also numerous in equa- 

 torial regions, and may be seen running briskly 

 about in hot, sandy, situations. Nor must we omit 

 to mention the Ants-proper, those memorable little 

 insects, which live in societies like the social bees ; 

 and the Social- Wasps, which manufacture galleries 

 of hexagonal cells out of paper, and surround their 

 cities with a wall ; and, lastly, the Honey-Bees, those 

 oft-quoted examples of industry, loyalty, and good 

 order, which live gregariously, and form elaborate 

 houses, to the robbery of which we owe our honey 

 and our wax. 



VI. ORDER CLEAR- WINGED INSECTS 

 (Hymenoptera). 



Wings four, naked, membranous, hind pair the 

 smallest and few- veined ; mouth with horny jaws, 

 and with a lower lip or tongue sheathed by the 

 maxillae ; abdomen in females armed with an ovi- 

 positor or sting ; tarsi usually five-jointed. Larva 

 usually vermiform, apodal ; pupa inactive, incom- 

 plete. 



