4th. =Lesions of the Spinal Cord.= Brown-Sequard determined epileptiform convulsions by transverse section of one-half of the spinal cord, or of its superior, lateral or inferior columns. The later development of the doctrine of interrupted spinal inhibition, suggests that, many of the seizures in question are but exaggerated spinal reflexes, which are no longer restrained by cerebral inhibition. That all are not of this spurious kind may be fairly inferred from his further demonstration that bruising of the great sciatic in animals tended to produce epilepsy. In such cases., the irritation of certain areas by pinching the skin, served to produce a seizure. Not only so, but the animals in which such artificial epilepsy had been induced tended to transmit the infirmity to their progeny. The prevailing view of epilepsy however, would consider such lesions as sources of peripheral irritation by which the brain is affected sympathetically, while the real explosion is the result of the sudden discharge of the pent up excitement caused in the encephalic centres by the irritation at such distant points. 5th. =Morbid States of the Circulating Blood.= Certain poisons, when brought in contact with encephalic nerve centres produce epileptic seizures. Gallerani and Lussana applied creatinin directly to the cerebral cortex and quickly induced epileptiform convulsions and choreiform movements. Injected subcutaneously it failed to produce the same effect. Cinchonoidin acted on the basal ganglia of the brain producing convulsions but no choreiform movement. Poisoning with lead, ergot, nitro-pentan, nitro-benzol and a number of other poisons brings about intermittent convulsive seizures. The same may be inferred of ptomaines and toxins, in the convulsions that appear in the advanced stages of infectious diseases (canine distemper, hog cholera, etc.). 6th. =Reflex Irritation.= Perhaps no peripheral irritation more frequently causes epilepsy, than parasites. In young dogs worms in the intestines (tænia cœnurus, tænia tenuicollis, tænia serrata, tænia echinococcus, and ascarides) have been especially incriminated. Also linguatula tænioides in the nasal sinuses. In young pigs the echinorrhynchus gigas, ascarides and trichocephalus. In horses ascarides have been principally blamed.