to the egg, which demands complete immobility in the provisions. Their
centres of innervation will therefore be stabbed as well, with the leisure
which the Mantis, now put out of action, permits. These legs, as well as
their nervous centres, are situated very far behind the first point
attacked. There is a long neutral interval, that of the prothorax, into
which it is quite useless to drive the sting. This interval has to be
crossed; by a backward movement conforming with the secrets of the victim's
internal anatomy, the second ganglion must be reached and then its
neighbour, the third. In short, the surgical operation may be formulated
thus: a first stab of the lancet in front; a considerable movement to the
rear, measuring about two-fifths of an inch; lastly, two lancet-thrusts at
two points very close together. Thus speaks the science of man; thus
counsels reason, guided by anatomical structure. Having said this much let
us observe the insect's practice.

There is no difficulty about seeing the Tachytes operate in our presence;
we have only to resort to the method of substitution, which has already
done me so much service, that is, to deprive the huntress of her prey and
at once to give her, in exchange, a living Mantis of about the same size.
This substitution is impracticable with the majority of the Tachytes, who
reach the threshold of their dwelling in a single flight and at once vanish
underground with their game. A few of them, from time to time, harassed
perhaps by their burden, chance to alight at a short distance from their
burrow, or even drop their prey. I profit by these rare occasions to
witness the tragedy.

The dispossessed Wasp recognizes instantly, from the proud bearing of the
substituted Mantis, that she is no longer embracing and carrying off an
inoffensive carcase. Her hovering, hitherto silent, develops a buzz,
perhaps to overawe the victim; her flight becomes an extremely rapid