With regard to ordinary nerve-wounds as a cause of neuralgia, we have already said (_vide_ Chapter II.) nearly as much as it is necessary to say; we need only here point out that, like the influence of cold applied to superficial nerves, that of wounds must necessarily be a depressing one to the centre with which the wounded nerve is connected, and the resulting neuralgia must be regarded as an expression of impeded and imperfect nerve-energy, not of heightened nerve-function. The pain is set up during the process of nerve-healing; that is to say, at a stage intermediate between those of abolished function and completely restored function; and there can be little doubt that the obstinacy with which it is often protracted is due to the slowness with which a wounded nerve recovers its full functional activity; when once the latter is completely restored there is an end of neuralgic pain. It is exactly analogous to the course of events in recovery from freezing. There remain for consideration, however, (a) a small class of cases of nerve-wounds in which the healing process is not simple; but the lesion is followed by the development of a tumor of the kind denominated true neuroma. The process consists of hyperplastic changes in the nerve-fibres; its commonest examples are seen in the extraordinarily painful swellings that occur on the ends of nerves left in stumps after amputations; but, in fact, a neuroma of this kind may occur after any kind of severe nerve-injury, as, _e. g._, a cut from broken glass, the impaction of foreign bodies, etc. The true neuromata are composed mainly of nerve-tissue, with a relatively small element of connective tissue: the nerve-fibres can be traced directly to the nerve-tumor. Besides the traumatic neuromata which form permanent tumors, incapable of being got rid of except by actual excision, a minor variety of the same kind of change has in several cases been known to take place in consequence of an abiding local irritation from the impaction of a foreign body, on the removal of which the neuromatoid enlargement completely disappeared. (b) There are likewise a certain number of cases in which a tumor is developed from the neurilemma, and does not consist of nervous tissue; these are distinguished as false neuromata, and may be of various kinds, the fibromatous and gliomatous being far the most common, but cysts and cystic tumors also sometimes occurring.