In the first place, the meningitis had affected practically all the posterior roots so that the explanation of the posterior column sclerosis of this case is clear. The meningitis had apparently been so marked, also, that all the fibres anywhere near the periphery of the spinal cord had been likewise destroyed. The posterior columns and the posterior root zones were markedly sclerotic; or as we say (having reference to the overgrowth of neuroglia tissue) gliotic. But there was as much sclerosis (gliosis) of the lateral columns (particularly in the posterior two-thirds) as there was in the posterior columns and root zones. In fact, the entire posterior half or two-thirds of the spinal cord markedly outstripped the anterior portions of the cord in the severity of the gliosis (sclerosis) shown. But although we can explain the posterior column sclerosis, the sclerosis of the posterior root zones and the marginal sclerosis (_Randsklerose_) round the entire periphery of the cord, on the basis of long-standing effects of old meningitis, we cannot thus explain another finding, namely, the destruction of the fibres in the lateral columns. This, in fact, is explained through lesions (mentioned below) that affected the encephalon. The net result of all these lesions of the spinal cord was to leave only the gray matter and a small amount of surrounding fibres (belonging to short tracts uniting nearby segments) intact. Briefly stated, =every long tract in the spinal cord appeared upon examination to be extensively degenerated=. The genesis of this parenchymatous loss was, however, double, being in part due to a local meningeal process (sometimes known as “perimeningitis”) and in part due to a cutting off of the pyramidal tract fibres on both sides by lesions higher up in the nervous system. [Illustration: CASE I. SPINAL CORD (THREE LEVELS) SHOWING: A. Marginal sclerosis—effect of old meningitis now extinct. B. Posterior column sclerosis—effect of meningitis about posterior roots also now extinct. C. Bilateral pyramidal tract sclerosis—effect of cerebral thrombotic lesions. Note distortion of tissues in B and C, partly artificial (tissues in places diffluent). ] =ANATOMICAL FORMULAE= =MENINGOVASCULOPARENCHYMATOUS INVOLVEMENT= M, V, P, or Combinations Applied to the Classification of Head and Fearnsides I. SYPHILIS MENINGOVASCULARIS CEREBRAL FORMS M or V or MV[3] HEMIPLEGIA V AFFECTION OF THE CRANIAL NERVES M MUSCULAR ATROPHY M LATERAL AND COMBINED DEGENERATIONS M EPILEPSY M or V