Direct observation is impracticable here. If we took it into our heads to dig and to uncover the abdomen at work, the mother, worried by our importunity, would leap away without telling us anything. Fortunately, one Locust, the strangest of my district, reveals the secret to us. I speak of the Tryxalis, the largest member of the family, after the Grey Locust.
Though inferior to the last-named in size, how far she exceeds her in slenderness of figure and, above all, in originality of shape! On our sun-scorched swards, none has a leaping-apparatus to compare with hers. What hind-legs, what extravagant thighs, what shanks! They are longer than the creature’s whole body.
The result obtained hardly corresponds with this extraordinary length of limb. The insect shuffles awkwardly along the edges of the vines, on the sand sparsely covered with grass; it seems embarrassed by its shanks, which are slow to work. With this equipment, weakened by its excessive length, the leap is awkward, describing but a short [[392]]parabola. The flight alone, once taken, is of a certain range, thanks to an excellent pair of wings.
And then what a strange head! It is an elongated cone, a sugar-loaf, whose point, turned up in the air, has earned for the insect the quaint epithet of nasuta, long-nosed. At the top of this cranial promontory are two large, gleaming, oval eyes and two antennæ, flat and pointed, like dagger-blades. These rapiers are organs of information. The Tryxalis lowers them, with a sudden swoop, to explore with their points the object in which she is interested, the bit which she intends to nibble.
To this abnormal shape we must add another characteristic that makes this long-shanks an exception among Acridians. The ordinary Locusts, a peaceful tribe, live among themselves without strife, even when driven by hunger. The Tryxalis, on the other hand, is somewhat addicted to the cannibalism of the Grasshoppers. In my cages, in the midst of plenty, she varies her diet and passes easily from salad to game. When tired of green stuff, she does not scruple to exercise her jaws on her weaker companions.
This is the creature capable of giving us [[393]]information about methods of laying. In my cages, as the result of an aberration due no doubt to the boredom of captivity, it has never laid its eggs in the ground. I have always seen it operating in the open air and even perched on high.[2] In the early days of October, the insect clings to the trelliswork of the cage and very slowly discharges its batch of eggs, which we see gushing forth in a fine, foamy stream, soon stiffening into a thick cylindrical cord, knotty and queerly curved. It takes nearly an hour to complete the emission. Then the thing falls to the ground, no matter where, unheeded by the mother, who never troubles about it again.
The shapeless object, which varies greatly in different layings, is at first straw-coloured, then darkens and turns rusty-brown on the morrow. The fore-part, which is the first ejected, usually consists only of foam; the hinder part alone is fertile and contains the eggs, buried in a frothy matrix. They are amber-yellow, about a score in number and shaped like blunt spindles, eight to nine millimetres in length.[3] [[394]]
The sterile end, which is at least as big as the other, tells us that the apparatus which produces the foam is in operation before the oviduct and afterwards goes on while the latter is working.
By what mechanism does the Tryxalis froth up her viscous product into a porous column first and a mattress for the eggs afterwards? She must certainly know the method of the Praying Mantis, who, with the aid of spoon-shaped valves, whips and beats her glair and converts it into an omelette soufflée; but in the Acridian’s case the frothing is done within and there is nothing outside to betray its existence. The glue is foamy from the moment of its appearing in the open air.
In the Mantis’ building, that complex work of art, it is not a case of any special talent, which the mother can exercise at will. The wonderful egg-casket comes from the ordinary action of the mechanism, is merely the outcome of the organization. A fortiori, the Tryxalis, in discharging her clumsy sausage, is purely a machine. The thing happens of itself.