278 Journal of Comparative Neurology. 



but of nerve-cells, in the healing wounds of the nervous sys- 

 tem (see Valenza, p. 32 and A. Tedcschi, anat. experimenteller 

 Beitrag zum Studium der Degeneration des Gewebes des Cen- 

 tralnervensystems. Ziegler's Beitr. z. path. Anat. Vol. XXI, 

 H. I, 1897) is hardly more than an object of curiosity. The 

 occurrence of more than one nucleus, not infrequent in the 

 sympathetic nervous system, very rare elsewhere, is also an 

 uncorrolated fact. (See further the latest summary of this 

 question : Sulla cariocinesi della cellule nervosi. Ricerche del 

 dott. Giuseppe Levi. Riv. di Pat. nerv. e ment., Marzo, 

 1898. 



Hodge has published a little study of the appearance of 

 human cells at various ages, only referring to the cell-body, 

 and on ground of three individuals. A diminution of the rela- 

 tive size of the nucleus in old age seems to be the best estab- 

 lished result. The strongest part of the life-history of the 

 neurone lies undoubtedly in the facts which led His to estab- 

 lish the neurone-theory from the embryological point of view 

 (see p. 121). 



There are a vast number of observations on experimental 

 and pathological alterations in various forms of nerve-cells in 

 the literature of the last two years, the effects of inanition, in- 

 toxications, diseases, etc. After summarizing the available 

 material, the writer finds that only a small number of leading 

 features throw any light on the neurone-theory. The majority 

 of studies deal merely with the changes in the cell-bodies in 

 preparations with Golgi's and Nissl's stains, or their modifica- 

 tions. 



The history of our knowledge of functional changes in 

 nerve-cells due to stimulation, exercise and intoxications has 

 been written a number of times in late years. The principal 

 contributions begin with Hodge, Mann, Vas, Nissl, Schafifer, 

 Pandi, Sarbo, Berkeley, etc. They have established processes 

 of fatigue and recuperation, of toxic disorganization with ter- 

 mination in death or recuperation, of very much the same char- 

 acter as those known in other cells of the body. About the 

 details there is much controversy. 



