• 7 blood vessels in healthy areas too often were much diseased (Bastionelli, Russell, Batten, and Collier, Jacob, Moxter, Vori Voss, Putna,m and Taylor). It was likewise sho\vn that in a great many cases there was no evidence, whatever, of hemorrhage (Russell, Batten, and Collier). • Relative to the lymph stasis theory, Lene! suggests that the swelling seen in the adventitial tissue may be only a stage in the "Abbauvorgang," and thus a result, rather than a cause, of the ner\'e lesions. An entirely different explanation is advanced by Rothmann, who found hemorrhages, atrophy, and destruction of the anterior horn cells in the gray matter. These, he argues, as does Teichmueller, are the changes which initiate the cycle of disintegration, while the alterations seen in the white matter are due simply to a resulting secondary degeneration. Ile insi sts further, that although these lesions are not always demon trable micro copically, the injury is there nevertheless, and the mechanism the same. Goebel, on the other hand, though he also demonstrated changes in the gray matter, refute thi idea by saying that the changes in the gray matter are often mis ing, that the inten ity and the localization of these changes do not correspond with tho e found in the white columns, and that in longitudinal section , the commi sural fibers are found to be intact. Additional evidence was supplied by Bastionelli, who noted that the white fibers were diseased only in the peripheral portion of the cord and that the gray matter, for this reason, could not be the primary seat of the degeneration. On account of the evidences of inflammation sometimes observed, and the occa ional febrile course, it is thought by ome (Boedeke and J uliusberger) that the process taking place here i really a true myelitis of the dis eminated type. This, N onne thinks, is also true of sepsis and senility. The fact, however, that inflammatory reaction, such as cell infiltration, is too often lacking, and that the gray matter is only exceptionally involved (Billings) argue against this view. Edinger, in support of his "Ersatztheorie" performed an experiment which has a direct bearing on the point under consideration. In the spinal cords of a number of rats, in which he produced an anemia, and which he then set to work by the ingenious device of suspending them by their tails, he found exlen ive degenerative changes, while in the cords of control rats, which were not anemic, no such changes could be detected. Finally, Dana has emphasized two other factors, which may be at work in this di ea e and which may be in trumental, first, in determining the characteri tic localization, and, second, in deciding which patients are to get a combined clero i , and which are to remain
