. A treatise on the nervous diseases of children : for physicians and students. the white matter will, no doubt, be necessary asour knowledge of the anatomy of the cord increases. For the present weare left with a large mass of white fibres which Flechsig terms the anteriorground fibres, to which we cannot as yet assign a positive function. Theydo not degenerate through any considerable extent of the cord, and as some ANATOMY OF THE SPINAL CORD. 273 of the fibres pass to the anterior commissure, in which a marked decussationtakes place, the fibres in these anterior ground bundles may serve to
. A treatise on the nervous diseases of children : for physicians and students. the white matter will, no doubt, be necessary asour knowledge of the anatomy of the cord increases. For the present weare left with a large mass of white fibres which Flechsig terms the anteriorground fibres, to which we cannot as yet assign a positive function. Theydo not degenerate through any considerable extent of the cord, and as some ANATOMY OF THE SPINAL CORD. 273 of the fibres pass to the anterior commissure, in which a marked decussationtakes place, the fibres in these anterior ground bundles may serve to connectthe two halves of the cord. The commissure lies between the bottom of the anterior fissure and theposterior columns. It consists of an anterior white portion and a posteriorgray portion. The white portion is largest in the lumbar region, and con-tains a large number of meduUated fibres which cross from the anterior halfof one side of the commissure to the posterior half on the other side. Theanterior commissure also contains fibres that connect the anterior white col-. FiG. 70.—Diagrammatic Cross-section of Spinal Cord, showing the Course of the MoreImportant Tracts within the Cord. (Slightly modified, after Edinger.) umns of one side with the anterior cornu of the other. Other fibres passthrough the commissure from one anterior pyramidal tract through the in-termediate gray substance into the lateral column, thus constituting a con-nection which is practically equivalent to a decussation (Fig. 70). The gray portion of the commissure contains very often medullated nerve-fibres, a number of which pass into the posterior horn of each side. Theseare continuous with the fibres in the posterior horns, and it is, therefore,likely that much of the sensory decussation in the cord is effected by thesefibres passing through the gray commissure. It has been customary to think of the structure of thespinal cord as represented by the appearance on cross-sec-18 274 ^^^ NERVOUS DISEA
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