And that this is the true view of the mat ter, would further appear from a careful exam ination into the nature of the phenomena which follow the section or injury of nerve trunks or centres, and which have been supposed to indicate the impossibility of the continuance of true nutritive operations after the withdrawal of the hypothetical nervous influence. In the first place, the effect pro duced by section of those nerves which are supposed to exert the greatest influence, is probably not in any case a simple suspension of the nutritive operations, nor a death of the part ; but it is of the nature of inflam matory action, involving disordered nutrition and perverted secretion. Further, this dis ordered condition does not seem to be the direct result of the paralysis of the nerves, so much as an indirect consequence of the want of power to resist morbific causes. " If the section of the sensitive nerves of a part," it has been observed (with special reference to the inflammations of the eye, the lungs, and stoinach, consequent upon section of the fifth pair and par vagum), " were the direct cause of its inflammation, we should expect to see in flammation in all parts of which the sensitive nerves are cut ; whereas the phenomenon in question is seen only in a few parts ; and in those parts it originates, and is chiefly seated, in a single texture, viz. the mucous mem brane : that membrane is distinguished from others in the body by its power of bearing the contact of air, of foreign substances, and of excretions elaborated within the body, with impunity. This power seems obviously con nected with its vital povver of throwing out, when irritated, a mucous secretion, which protects it f q u ally as the cuticle protects the true skin ; and this adaptation of the quantity of protecting mucus to the irritation which may act on a mucous membrane, may be very naturally supposed to depend on its sensi bility, and to cease when its sensitive ncrves are divided, and allow the mucous membrane to inflame and slough, equally as a serous membrane would do from the irritations which, in the natural state, excite only a healthy action upon it. On this supposition, the inflammations in question depend, not simply and directly on the division of nerves, but, on the action of the air, the food, the bile, &c., on mucous menibranes deprived of
their sensibility, and thereby in great measure of their protecting mucus ; and bear an analogy to the inflammations of the same membranes which frequently take place from deficiency of the mucous secretion, in cases of death by starvation, and towards the close of lingering and exhausting diseases."* And lastly, even supposing the inflammatory changes to be the direct result of the paralysed state of the nerves, they in themselves affbrd conclusive evidence against the doctrine, that the nervous influence is essential . to the nutritive and secretory operations ; for, as Bichat observed, respecting the inflammation and suppuration of the testicle after its complete isolation from the larger masses of the nervous system, the establishment and maintenance of a morbid secretion was just as conclusive evidence of the independent character of the process, as if the normal product of the testis had been continued.* Upon all these grounds we feel justified in asserting, that no adequate ground has yet been furnished by patholog,ical observation and experiment, for the establishment of any other doctrine as to the relation between the nervous system and the organic functions, than the last of those just stated. It is perfectly conformable to the facts supplied by com parative physiology, and by the history of developement ; and may be said to rest upon them as upon a broad foundation. It har monises sufficiently well with the results of experiinent and pathological observation on inan and the higher animals, to be considered as giving the most satisfactory interpretation of them which, in the present state of our knowledge, seems likely to be attained ; and if it he not the whole truth, is evidently not far from it. On the other hand, the doctrine that nervous influence is essential to the per formance of the nutritive and secretory oper ations, is opposed to the mass of phenomena presented in the vegetable world, in the lower tribes of the animal creation, and in the his tory of the developement of the higher ; to the exact knowledge we now possess of the structure of glands themselves ; and even to the results of those experiments and patho logical observations which have been relied upon to prove it, when these are carefully sifted. (W. B. Carpenter.)