THE PHYSIOLOGY OF THE NEURON. 523 



or beaded, the gemmules being very scarce or absent. Here, 

 again, is a condition which, as does fatigue, morphine, and, we 

 may add, chloroform, chloral hydrate, and other toxics used 

 by Demoor and others with similar results, all tend in the one 

 direction: i.e., to morbidly reduce functional activity. This is 

 a well-known characteristic of the bromides. In a study of the 

 cortical cells under the influence of poisonous doses of potas- 

 sium bromide, H. K. Wright 26 says: "If the primal ascending 

 dendron is followed to its visible termination, several ampullous 

 or varicose swellings of varying size are met with," . . . 

 "on the basal processes also varicosities are to be seen; but 

 they are small and, like those of the ascending protoplasmic 

 process, are sharp in outline, and shorn of the lateral projec- 

 tions which obtain on the unaltered part of the extensions. 

 One may be seen pn each secondary branch, and ranges in size 

 from a small and scarcely recognizable to a readily obvious swell- 

 ing. None of them, however, reach the dimensions of the 

 apical projection and its branches." 



If the method of staining is the cause of all this, we are 

 brought to the conclusion that it must be selective as to the 

 parts of the dendrite it affects, and that only functionally- 

 impaired cells are so affected by the stain as to show varicosi- 

 ties. Even then staining methods would furnish precious in- 

 dications. But it seems clear to us that, while the newer 

 chrome-silver methods still furnish imperfect pictures of the 

 morbid alterations of the neuron, they cannot with justice be 

 said to either cause or prevent the formation or disappearance 

 of gemmules and varicosities; in other words, that they are 

 not artifacts of the Golgi method. The marked tendency of 

 the swellings to locate at the apices, and the gradual reduc- 

 tion of the varices as the cell-body is approached recall, on the 

 other hand, a well-known pathological principle: i.e., that the 

 morbid effects of impaired general nutrition are first felt by 

 terminal structures. 



And the painstaking experiments of Weil and Frank do 

 not appear to us in the least to prove their conclusions that 

 "the varicosities must be regarded as artifacts" and that "they 



28 H. K. Wright: Brain, Summer, 1898. 



