Second, the =autopsy proof=. Many dissections have been made and autopsies held with the view of discovering the character and the potency of the osteopathic lesion. This very important work has borne out the osteopathic theory of disease. Vertebral and rib displacements have been noted, corresponding ligamentous tissues thickened, associated nerve tracts and vascular channels disturbed, and finally the related organ found diseased.[23] Third, the =experimental proof=. Experimental proof appeals, logically, to the scientific mind. This proof[24] is being gradually developed. Experimental investigation has been successfully carried out upon numerous animals. The experiments conclusively prove that not only spinal inhibitory and stimulatory manipulations (mechanical) are productive of immediate physiological changes in the viscera, but that the structural anatomical lesion or noxa is an important factor in the etiologic field. Pathological changes in several organs directly follow the artificially produced vertebral and rib lesions, showing beyond doubt the reality and effectiveness of the osteopathic lesion. This emphasizes the point that centrifugal impulses originate an inflammation in a previously healthy and uninjured tissue or viscus. And as “inflammatory phenomena may be sympathetically developed in regions innervated from the same area in the brain or spinal cord” it remains to prove the actuality of vertebral and rib lesions, i. e., structural perversions really affect contiguous nerve courses and vascular channels; and this has been demonstrated in laboratory experiments and at the autopsy. Consequently the vertebral, rib, or other lesion may be an important etiologic factor either to the nerve strand from cord or brain to viscus or from viscus to cord or brain. Dr. Still says in his Autobiography that “all nerves depend wholly on the arterial system for their qualities, such as sensation, nutrition and motion, even though by the law of reciprocity they furnish force, nutrition and sensation to the artery itself.” It matters little in this outline whether obstruction to nervous integrity is by way of an impinged artery or by direct pressure, or both, or otherwise, for the primary consideration is the noting that the osteopathic lesion is a real and potent factor of disease. Sajous[25] informs us that “a neurone is directly connected with the circulation (via neuroglia-fibril) by one or more of its dendrites, which serve as channels for blood plasma,” that a neurone receives its nutrition directly from the general circulation, and that from the axone the blood passes into a lymph space connected with a vein. Thus in reality a part of the circulatory system is that of the entire cerebrospinal system.