Proceedings of the fourteenth annual session of the Association of American Anatomists : held at Anatomical Laboratory of Johns Hopkins University, Baltimore, Md., December 27 and 28, 1900.

  • Association of American Anatomists. Annual Session 1900 : Baltimore, Md.)
Date:
1901
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Licence: In copyright

Credit: Proceedings of the fourteenth annual session of the Association of American Anatomists : held at Anatomical Laboratory of Johns Hopkins University, Baltimore, Md., December 27 and 28, 1900. Source: Wellcome Collection.

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    brain to the cord, and various theories were brought forward to explain it. It was considered probable by some anato- mists that the pyramidal tract divided at the decussation, some fibres passing to the lateral column of each side, while a portion remained in the anterior column as the direct tract; but in the absence of confirmation Sherrington’s theory of “ recrossed ” fibres was generally accepted. Sherrington's conclusions were based upon experimental unilateral lesions on the brain of the monkey, in which he claimed that im- mediately below the decussation the degeneration was all on the opposite side of the cord, while at a still lower level degenerated fibres were found in both lateral columns. He thereupon assumed that all the degeneration crossed over in the decussation to the opposite side of the cord, but a portion crossed back at a lower level to the lateral column of the same side. The probable explanation of his mistake is that at the time of his observations the delicate methods in use in recent years were not known. Still the fact that he reported at the same time that fibres from the upper limb area of the cortex passed down the entire length of the cord, while fibres from the leg areas disappeared from the cord in the cervical and upper dorsal regions, would indicate that his preparations were handled or studied somewhat carelessly. It is rather curious that no one seems to have suggested that he had mixed up those cords. Soon after the publication of Marchi’s method of staining degenerated nervous tissue by osmic acid, Muratow undertook the study, by that method, of degenerations following lesions of the brain in the dog. He published the results of his observations in 1893 1 and clearly showed that in the dog the pyramidal tract divided at the decussation and a portion passed directly to the lateral column of the same side. I had been working with the same method tracing degenerations in the central nervous system of the monkey after very minute lesions of the cerebral cortex, and at the time of the appear- ance of Muratow’s publication I had already accomplished the same results on the monkey, but to him undoubtedly ] Arcliiv fur Anatomie und Entwickelungsgeschiclite. 1803.