In vain, then, do our Darwinian humanizers of the brute exalt instinct at the expense of intelligence. Their attempt to reduce to a difference of degree the difference of kind that separates the irrational from the rational, fails all along the line. Indeed, far from being able to account for the appearance of intelligence in the world, transformistic theories are impotent to account for so much as the development of instinct, all forms of the evolutionary theory, the Lamarckian, the Darwinian, the De-Vriesian, etc., being equally inadequate to the task of explaining the origin of animal instincts. The complex instinctive behavior of predatory wasps, for example, is absolutely essential for the preservation of their respective races, and yet these indispensable instincts are completely useless in any other than the _perfect state_. From their very nature, therefore, they do not admit of _gradual development_. The law of all, or none, holds here. “Instinct developed by degrees,” says Fabre, “is flagrantly impossible. The art of preparing the larva’s provisions allows none but masters, and suffers no apprentices; the Wasp must excel in it from the outset or leave the thing alone.” (“The Hunting Wasps,” p. 403.) To be useful at all, the instinctive operation must possess an indivisible perfection, which cannot be partitioned into degrees. The _Pompilius_ (_Calicurgus_), for instance, must, under penalty of instant death, take the preliminary precaution to sting into inaction the ganglion that controls the poison forceps of her formidable prey, the Black Tarantula (_Lycosa_), before she proceeds to paralyze it by stabbing its thoracic ganglion. The slightest imperfection or shortcoming in her surgery would be irretrievably disastrous. Such an instinct never existed in an imperfect form. The first wasp to possess it must have been an expert, or she would never have lived to serve the limp body of the huge spider as living provender for her tiny grub. “The first to come to grips with the Tarantula,” says Fabre, “had an unerring knowledge of her dangerous surgery. The least hesitation, the slightest speculation, and she was lost. The first teacher would also have been the last, with no disciples to take up her art and perfect it.” (“Bramble Bees,” p. 354.)