178 fotirnal of Comparative Neurology and Psychology. 



intensity witli the duration of the anemia. The modifications of least 

 intensity consisted in the appearance of swellings along the dendrite 

 which made its contour irregular. As this condition became more in- 

 tensified the swollen regions of the dendrites became fusiform and 

 then spherical. During this process the connecting regions between 

 the enlargements of the dendrites became more attenuated till a final 

 beaded or moniliform condition resulted. This modification he con- 

 sidered pathological. 



In another article ('98) upon the modification of the dendrites 

 under the influence of narcotics Soukhanoff reports in considerable 

 detail the results of nine experiments upon mice, rabbits and guinea 

 pigs. These animals had been subjected to the vapor of ether, chloro- 

 form or alcohol for various periods of time. Two of the experiments 

 were made by injection of trional. As a result of these experiments 

 and of a critical review of the work of other investigators, Soukha- 

 noff draws the following conclusions: (i) The moniliform condition 

 may occur in certain dendrites under normal conditions, a conclusion 

 reached by practically all authors; (2) under the influence of ether, 

 chloroform or alcohol there is not a very appreciable increase in the 

 moniliform condition; (3) injection of trional causes a monihform con- 

 dition of nearly all the dendrites of the cerebral cortex; (4) this change 

 is accompanied by a more or less complete loss of the gemmules; 

 (5) a loss in weight in guinea pigs subjected to trional injections can 

 be attributed only to profound nutritive derangement. This suggests 

 that the moniliform condition of dendrites may be "une degeneres- 

 cence sui generis" manifested whenever nutrition is severely affected. 

 A third contribution by Soukhanoff ('98) deals with the varicose 

 atrophy of the dendrites in the cerebral cortex under pathological con- 

 ditions. His pathological studies were checked by examination of a 

 normal specimen. From an exhaustive study of the latter case he 

 concluded that the moniliform condition of the dendrites is occasional- 

 ly found under normal conditions, but that it is very slight and not 

 to be compared with that found in cases of poisoning. From nine ex- 

 periments upon guinea pigs which had been subjected to arsenic poison 

 in varying degrees for periods of from six to thirty-three days, he con- 

 cludes that in acute and subacute poisoning by arsenic there occurs a 

 moniliform degeneration of the dendrites of the cerebral cortex. This 

 is very slight in some eases, but very marked in others. This diff'er- 

 ence cannot be accounted for by difference in the duration of the pois- 

 oning. Its cause is more likely to be found in individual differences 

 in the specimens as regards resistive power and general health. 



