102 



and note the frenulmn hook on the fore wing, which receives 

 the tip of the frenulum. It may be necessary to remove 

 some of the hairs from the base of the wing. Use a small 

 sable brush for this. 



Study the unbleached wings of the female, and note the 

 absence of a frenulum hook. 



Compare the hind wing of the monarch butterfly with the 

 hind wings of these moths, and discuss the differences be- 

 tween them. 



THE WINGS OF HYMENOPTERA. 



The determination of the homologies of the wing-veins of 

 Hymenoptera is very difficult ; as even in the most general- 



I / } ^ 



"JdA 



23 A' 



Fig. 6. — The veins of a typical hymenopterous wing. 



ized of the living members of the order, the venation of the 

 wings departs widely from the primitive type. For this 

 reason no student should begin his study of the venation of 

 wings with hymenopterous insects. In the following dis- 

 cussion it will be assumed that the student has carefully per- 

 formed the work on the wings of Diptera outlined in the 

 preceding pages ; and the first step for him to take at this 

 point in his studies is to take his drawings of dipterous 

 wings and review that work. 



