her threshold, therefore, prepared to beat a quick retreat if necessary, she watches for the favourable moment; she waits for the big Bee to face her, when the neck is easily grabbed.  If this condition of success offer, she leaps out and acts; if not, weary of the violent evolutions of the quarry, she retires indoors.  And that, no doubt, is why it took me two sittings of four hours apiece to witness three assassinations.

Formerly, instructed by the paralysing Wasps, I had myself tried to produce paralysis by injecting a drop of ammonia into the thorax of those insects, such as Weevils, Buprestes, {13} and Dung-beetles, whose compact nervous system assists this physiological operation.  I showed myself a ready pupil to my masters’ teaching and used to paralyze a Buprestis or a Weevil almost as well as a Cerceris {14} could have done.  Why should I not to-day imitate that expert butcher, the Tarantula?  With the point of a fine needle, I inject a tiny drop of ammonia at the base of the skull of a Carpenter-bee or a Grasshopper.  The insect succumbs then and there, without any other movement than wild convulsions.  When attacked by the acrid fluid, the cervical ganglia cease to do their work; and death ensues.  Nevertheless, this death is not immediate; the throes last for some time.  The experiment is not wholly satisfactory as regards suddenness.  Why?  Because the liquid which I employ, ammonia, cannot be compared, for deadly efficacy, with the Lycosa’s poison, a pretty formidable poison, as we shall see.

I make a Tarantula bite the leg of a young, well-fledged Sparrow, ready to leave the nest.  A drop of blood flows; the wounded spot is surrounded by a reddish circle, changing to purple.  The bird almost immediately loses the use of its leg, which drags, with the toes doubled in; it hops upon the other.  Apart from this, the patient does not seem to trouble much about his hurt; his appetite is good.  My daughters feed him on Flies, bread-crumb, apricot-pulp.  He is sure to get well, he will recover his strength; the poor victim of the curiosity of science will be restored to liberty.  This is the wish, the intention of us all.  Twelve hours later, the hope of a cure increases; the invalid takes nourishment readily; he clamours for it, if we keep him waiting.  But the leg still drags.  I set this down to a temporary paralysis which will soon disappear.  Two days after, he refuses his food.  Wrapping himself in his stoicism and his rumpled feathers, the Sparrow hunches into a ball, now motionless, now twitching.  My girls take him in the hollow of their hands and warm him with their breath.  The spasms become more frequent.  A gasp proclaims that all is over.  The bird is dead.

There was a certain coolness among us at the evening-meal.  I read mute reproaches, because of my experiment, in the eyes of my home-circle; I read an unspoken accusation of cruelty all around me.  The death of the unfortunate Sparrow had saddened the whole family.  I myself was not without some remorse of conscience:  the poor result achieved seemed to me too dearly bought.  I am not made of the stuff of those who, without turning a hair, rip up live Dogs to find out nothing in particular.