ii Journal of Comparative Neurology. 



tion of phosphomolybdic acid to each 60 cc. of one per cent, argentic 

 nitrate solution in distilled water. The second solution is made only as 

 needed and at the moment before placing the brain tissue in it." 



This method is said to avoid the perplexing fringe of brown about 

 the impregnated cells and is rather a stain than a precipitation. It is 

 said to be more reliable also. 



Unaltered cells fall into several groups : arkyochromic cells, with a 

 reticular arrangement of the chromophilic particles ; stichochromic cells , 

 with the particles in rows ; cytochro7nic cells, with large nucleus and small 

 cell body ; somatochromic cells, with much protoplasm and small nucleus. 

 The cortical cells are chiefly somatochromic of the stichochromic va- 

 riety. 



In the normal brain the contour of the vessels is regular and the 

 perivascular spaces are narrow but distinct. The nuclei of the walls 

 are sharply stained. In the alcoholic brains the small capillaries are 

 shrunken and irregular. The nuclei are swollen and absorb more stain. 

 The perivascular spaces are enlarged and are either empty or partly 

 filled with hsematoidin debris. In the somatochrome cells the nuclei 

 are altered in the disposition, size, and regularity of contour of the nu- 

 cleolar chromophilic particles. 



By the silver method Berkley claims to show that all the pyramidal 

 cells of the cortex and many of the irregular and angular ones have 

 short rectangular or oblique projections or gemmulte given off from the 

 protoplasmic processes and that these are not as Kolliker supposed ab- 

 normal or artifacts. Besides these the nerve cells have upon their 

 branches a small, though variable number of varicosities. 



The neuroglia cells have nodosities in their fibres which must be 

 carefully differentiated. Making all possible allowances for artifacts 

 and variability the author feels justified in considering a considerable 

 number of the appearances in the silver preparations of alcoholic brains 

 abnormal. The principal lesions are diminution in size, shrinkage of a 

 vast majority of the cortical cells, disappearance of the gemmulae, cer- 

 tain swellings of the neurodendrites, and roughening of the stronger 

 processes, and to some extent of the cell body. It is a question 

 whether cells undergoing degeneration are as readily impregnated as 

 the normal. Our own experience would lead to the conclusion that 

 active processes, whether normal or pathological, favor reactions while 

 an inert condition due either to fatigue or disease predispose to rejec- 

 tion of the stain. 



Tumefaction of the neurodendrite and a loss of the gemmulse go 

 hand in hand during degeneration. The method employed seems to 



