CRITICAL REVIEW OF THE DATA AND GENERAL 

 METHODS AND DEDUCTIONS OF MODERN NEU- 

 ROLOGY. 



By Dr. Adolf Meyer, 



Worcester Insane Hospital, Worcester, Mass. 



Fart II, With Plates XX and XXI. 

 (Continued from p. 148). 



The Nervous System as a Tissue. 



Of all the tissues of the human body the nervous system 

 is no doubt the least homogeneous one. Comparing one cubic 

 millimeter of liver with another we would find for all we know 

 now, the same oneness of liver-cells, of capillaries, of bile- 

 ducts ; there may be variations of size of the elements but not 

 many types. The kidney may be a little richer in architec- 

 tural forms and variations of the tissue-types — vessels and epi- 

 thelia : or the lymph gland with its lack of architecture along 

 hard lines of form has at least a sameness of principle and ele- 

 ments. The nervous system too has a certain homogeneous- 

 ness. White matter compares easily with white matter ; there 

 are differences in the number of vessels, of various sizes of 

 fibers and collaterals and the quantity and character of neuro- 

 glia and the manner of interlacing. But when we come to the 

 'gray matter' and its many shades passing over into 'white 

 matter,' we get a great number of types, as our outline of the 

 known neurone-types will make us expect : cells of great differ- 

 ences and therefore so characteristic for the locality in which 

 they are seen. 



Let us start in any section from a picture obtained with a 

 nuclear stain and attempt to classify all the cell-elements. This 

 task is by no means easy. To be sure, we know the well de- 

 veloped cell-types ; but the transition forms ? Starting with 

 the mesoblastic tissue, we find the blood-vessels and their 



