Objects for the Microscope. Ill 



Ichneumon-flies, and Gall-flies. It is a most interesting 

 group in the insect world, extremely intelligent, and com- 

 missioned by its Creator to minister to our comfort and to 

 defend us from injury in a way that is little known beyond 

 the labours of the Honey-bee. 



The Hymenoptera are distinguished from all those which 

 are called flies, by having four wings instead of two, 

 wholly membranous, veined, and divided into cells, but not 

 assuming the appearance of network, as do those of the 

 Dragon-fly, the Hemerobius, the Ephemera, or May-fly ; 

 neither are they veined at all like the wings of the real 

 fly (Diptera), yet the plan is perfect, both to distinguish 

 the group, and in that group the species from each other, as 

 we shall presently prove. The eyes are large and compound 

 in all the Hymenoptera ; they have generally three simple 

 eyes, or ocelli, on the crown of the head ; the jaws are 

 strong ; the tongue of varied structure (see Tongue of Bee 

 and Wasp), because the mouth organs are used not only 

 for food, but also for labour in the structure of nests, and 

 in providing for their young. The feet are somewhat like 

 those of the Diptera, but are sometimes terminated by 

 toothed claws (see Foot of Ophion) ; the tibia are often 

 armed with spines, or very curious spur-like appendages, 

 especially in these Saw-flies, and the tarsi are five-jointed. 

 As a rule they all feed upon flowers, but I have found them 

 very voraciously attacking insects in the hot sunshine of a 

 June morning. 



Their metamorphosis is complete ; that is, they lay eggs, 

 become larvae with six-hooked feet, spin a cocoon, and 

 change to pupa ; then rise up and go forth winged and 

 perfect. 



The wing of the Hymenoptera is the most important 

 part in ascertaining the genera, for all the antenna? are 

 long, varying from thirteen joints to as many as sixty or 

 seventy. They vibrate with singular sensitiveness, but are 

 not like those of the Diptera, wliere the antennae alone will 

 often decide a fly, and the minute differences of their struc- 

 ture is in itself a study. 



Here the index to God's order is in the wing, and if the 



