Meyer, Data of Modan Neurology. 115 



rone-theory was advanced, we may quote the short summary of 

 the text-book of physiology of Landois, edition of 1887. 



' ' The nervous elements present two distinct forms : nerve- 

 fibers, non-meduUated or medullated, and nerve-cells of various 

 forms and functions. An aggregation of nerve-cells constitutes 

 a nerve-ganglion. The fibers represent a conducting apparatus 

 and serve to place the central nervous organs in connection with 

 peripheral end-organs. The nerve-cells, however, besides trans- 

 mitting impulses, act as physiological centers for automatic 

 and reflex movements, and also for the sensory, perceptive, 

 trophic, and secretory functions." After a detailed description 

 of the histology of the nerve-fibers, the writer says concerning 

 the development of nerve-fibers : " At first nerve-fibers consist 

 only of fibrils, i. e. of axis-cylinders, which become covered 

 with connective substance, and ultimately the white substance 

 of Schwann is developed in some of them. The growth of the 

 fibers takes place by elongation of the individual interannular 

 segments, and also by the new formation of these." No hint 

 is given of the origin of all the fibers from nerve-cells. "The 

 ganglionic or nerve-cells have partly been considered as cells, 

 partly as more complicated structures. We distinguish multi- 

 polar and bipolar nerve-cells, nerve-cells with connective tissue 

 capsule and ganglionic cells with spiral fibers. The large cells 

 of the spinal cord have among their processes one non-ramified 

 'axis-cylinder process ' which becomes the axis-cylinder of a 

 medullated nerve-fiber. Whether the cerebral nerve-cells have 

 such processes is still doubtful, etc." 



This statement is repeated in the later editions. The 

 American one of 1892 gives merely a few editorial remarks in 

 parentheses, to the effect that * His and Forel claim that the 

 protoplasmic processes do not anastomose but are merely in 

 contact with one another,' and a statement that 'it is now cer- 

 tain that the cerebral cells too have processes. ' It is very grat- 

 ifying on the other hand, that W. T. Gowers, in the first edi- 

 tion of his "Manual of Diseases of die Nervous System," 

 1886, gives a view which has not received due attention in its 

 day but was in many ways a perfect anticipation of the present 



