64 Wisconsin Academy of Sciences, Arts and Letters, 
wings slightly spread apart, basking in the hot sunshine on the 
leaves at the tips of the highest branches. If a male, for 
some reason or other, takes to wing, oftentimes one or sev¬ 
eral other males will also leave their resting place, and, hol¬ 
ering about one another, will rise high into the air, only finally 
to come down again and take another sun bath on the leaves 
at the tops of the willow trees. The females are often found 
busily engaged in depositing their eggs, usually above the 
lower epidermis of the leaves. Oftentimes, however, they may 
be found girdling branches with their strong mandibles. 
DEPOSITION OF THE EGGS. 
The female usually assumes a very characteristic position 
in the act of oviposition. During the operation, she perches 
herself upon the margin of the leaf and always with her body 
in its longitudinal direction. The claws and tarsi of the three 
legs on one side of the body hold on to the dorsal surface of 
the leaf, while the margin of the leaf is usually held in the 
joint between the femur and tibia of these same legs. The 
claws of the three legs on the other side of the body usually 
cling to the mid-rib on the ventral surface of the leaf. Being 
perched in this position, she curls up the abdomen, places the 
distal end of the scabbard-like sheaths of the saws against the 
ventral surface of the leaf near its margin and then shoves out 
the saws obliquely. By an alternating movement of the two 
saws, one being thrust forward while the other is retracted, she 
begins to cut an incision above the lower epidermis. Each 
saw slides up and down in a groove to steady it. This groove 
is found within the supports of the saw, the pair of supports 
being united at the base. The insect during the sawing act 
often lets go and again catches hold with its claws as if to 
secure a better footing. Farther and farther she passes her 
ovipositor towards the mid-rib until she has passed it into the 
leaf its whole length, and then she widens out the cavity. 
Finally the saws cease to move, and the receptacle is completed. 
The abdomen contracts a few times, and then a pale-greenish 
egg appears near the distal end of the saws. The saw sways 
across the receptacle as the egg is being passed out, and then 
