( cxlva } 
of the stem transversely, the insect standing practically on 
the apices of its tibiae, which themselves were perpendicular 
to the stem. The wings were folded; the antennae evenly 
porrected and motionless—as indeed was the whole insect, 
except the apex of its abdomen—during the entire process. 
No part of the creature actually touched the stem, except the 
tarsi and the apices of the tibiae, until the work actually 
commenced ; head, thorax, and abdomen formed, as it were, 
a straight line, parallel to the longitude of the stem. 
Presently the apex of the abdomen was moved slowly, as 
though in hesitation, towards the stem, till the hairs clothing 
the apical plates of the saw-sheath (but not these plates them- 
selves !) appeared to touch it. I was convinced, and so still 
am, that these hairs were feeling and exploring the material 
with their sensitive tips. After a moment or two, the insect 
seemed to have satisfied itself that all was as it should be. 
The saw-sheath was again lifted into its original position,’ 
and the scalpellum was gradually protruded—looking exactly 
like the blade of a penknife as one opens it, only that its 
cutting edge (or rather edges) faced away from, and not 
towards, the handle—till it stood out at right angles to its 
sheath (or as nearly so as can be stated of an object which 
was not strictly rectilinear). Next, it was driven or pushed, 
not all at once but by a succession of stabs, into the stem 
(as a nail is by a hammer—the hammer in this case being the 
whole tip of the abdomen), until it was completely embedded 
in the stem, and the base of the saw-sheath was in actual 
contact with the latter, so that progress in this direction was 
necessarily now arrested. It did not pierce the stem directly 
towards its centre, but somewhat obliquely (on this occasion 
on the right of the insect’s body, but in other cases I have 
seen it turned towards the /eft/). Consequently no part of 
the scalpellum became much more deeply sunk below the 
surface of the stem than another; and its apex was at all 
times as clearly visible as its base. Directly it entered the 
stem (the tip of the support, as I think, actually commencing 
the incision) the saws began to slide backwards and forwards, 
driving their pointed tips further and further into the material, 
of course in the same direction as that in which the whole 
