alive but harmless. A narrow and very long prothorax divides the front pair
of legs from the two hinder pairs. There must therefore be an isolated
ganglion in front and two ganglia, close to each other, about two-fifths of
an inch back. Dissection confirms this forecast completely. It shows us
three fairly bulky thoracic ganglia, arranged in the same manner as the
legs. The first which actuates the fore-legs, is placed opposite their
roots. It is the largest of the three. It is also the most important, for
it presides over the insect's weapons, over the two powerful arms, toothed
like saws and ending in harpoons. The other two, divided from the first by
the whole length of the prothorax, each face the origin of the
corresponding legs; consequently they are very near each other. Beyond them
are the abdominal ganglia, which I pass over in silence, as the operating
insect does not have to trouble about them. The movements of the belly are
mere pulsations and are in no way dangerous.

Now let us do a little reasoning on behalf of our non-reasoning insect. The
sacrificer is weak; the victim is comparatively powerful. Three strokes of
the lancet must abolish all offensive movement. Where will the first stroke
be delivered? In front is a real engine of warfare, a pair of powerful
shears with toothed jaws. Let the fore-arm close upon the upper arm; and
the imprudent insect, crushed between the two saw-blades, will be torn to
pieces; wounded by the terminal hook, it will be eviscerated. This
ferocious mechanism is the great danger; it is this that must be mastered
at the outset, at the risk of life; the rest is less urgent. The first blow
of the stylet, cautiously directed, is therefore aimed at the lethal fore-
legs, which imperil the vivisector's own existence. Above all, there must
be no hesitation. The blow must be accurate then and there, or the
sacrificer will be caught in the vice and perish. The two other pairs of
legs present no danger to the operator, who might neglect them if she had
only her own security to think of; but the surgeon is operating with a view