Delirium or derangement of emotional or mental functions is usually the result of organic disease of the brain and especially of the cortical gray matter of the cerebrum. It is seen in hyperæmia, anæmia, faults of nutrition, intoxications and variations of temperature. The derangements of circulation may be in the meninges or in the nervous substance. The intoxications may be with mineral (lead, mercury), vegetable (opium, Indian hemp, belladonna, hyoscyamus, stramonium, strychnia), or other poisons, including the toxic products of microbes (as in pneumonia, scalma, rabies, influenza, Rinderpest, milk sickness, Texas fever, etc.). _Symptoms._ These are usually an extraordinary and disorderly nervous excitement. =Horses= take expectant or ready positions of the limbs, plunge with feet in rack or manger, rear, turn, kick, bite, spring violently, neigh, and push or knock the head against the wall. =Cattle= bellow in a loud or frightened manner, attempt to kick and gore, grind the teeth and make movements of the jaws, froth at the mouth, dash themselves in any direction heedless of obstacles, push the head against the wall breaking teeth or horns, and moving heedlessly against fences, or trees, or into water or pits even to their own destruction. =Sheep= stamp the feet, butt, bleat, work the jaws, grind the teeth, leap, and move in a given direction regardless of obstacles. =Pigs= grunt, tremble, champ the jaws, run against obstacles, scratch the ground with their feet or snout and creep under the litter. They may even attempt to bite. =Dogs= are restless, whine, move in a circle, snap at straw, bars, doors, and other objects, and may show a disposition to bite. In all the domestic animals these delirious symptoms may closely resemble those of rabies. This has been particularly noticed in certain forms of poisoning. Pascault has found this in cattle that had eaten garlic and Cadeac in dogs that had eaten tansy. The animals in such cases become morbid, dull, taciturn, they become usually hypersensitive, sometimes hyposensitive, have a change of voice, and show a readiness to resent and bite if interfered with, and even to wander away by themselves as in rabies. On the other hand they may be seized with lethargy and torpor as in dumb rabies, and with or without access of convulsions may pass away in a condition of paralysis. Among other conditions these symptoms have been found to be associated with epilepsy, foreign bodies in the pharynx, gullet, stomach or bowels, with intestinal parasites, or with mycotic poisoning (ergotism, smut, the fungus of coniferous trees, etc.).