HYMENOPTERA. 387 



where it joins the thorax. Their wings are long, narrow, and 

 strong, and overlap on the top of the back, when closed. The 

 body is very long, and nearly or quite cylindrical ; the thorax and 

 the after part of the body are of equal thickness, and are closely 

 joined together. The horn, at the end, is short, and conical or 

 triangular, in the males ; longer, and sometimes spear-pointed, in 

 the females. Moreover the latter are provided with a long, cy- 

 lindrical borer, hinged to the middle of the belly, which is fur- 

 rowed to receive it. The borer usually extends some distance 

 beyond the end of the body, and consists of five pieces. The 

 two outermost are grooved within, and, when shut, form a hollow 

 tube or scabbard to the others, one of which represents the two 

 backs of the saws of the saw-flies, joined together, and encloses 

 two needles for boring holes. The part, serving for a back to 

 these needles, is notched on each side, and the needles them- 

 selves, which are as fine as a hair, and as strong and elastic as 

 wire, have several small teeth along the lower side towards the 

 end. These needles, and the back in which they play, are so 

 connected as to appear to be only a single spear-pointed awl. 

 With this complicated and powerful tool the females bore holes 

 into the trunks of trees, wherein they drop their eggs. Their 

 young are cylindrical and fleshy grubs, of a whitish color, with a 

 small, rounded, horny head, and a pointed and horny tail. They 

 have six very small legs under the forepart of the body, and are 

 provided with strong and powerful jaws, wherewith they bore 

 long holes in the trunks of the trees that they inhabit. Like 

 other borers, these grubs are wood-eaters, and often do great 

 damage to pines and firs, wherein they are most commonly found. 

 When fully grown, the grubs make thin cocoons of silk, inter- 

 woven with little chips, in their burrows, and in them go through 

 their transformations. The chrysalis is somewhat like the winged 

 insect in form, but is of a yellowish white color, till near the time 

 of its last change, and the wings and legs are folded under the 

 breast ; in all these respects it agrees with the chrysalids of other 

 Hymenopterous insects. After the chrysalis skin is cast off, the 

 winged insect breaks through its cocoon, creeps to the mouth of 

 its burrow, and gnaws through the covering of bark over it, so 

 as to come out of the tree into the open air. It is slated that the 



