Ill Journal of Comparative Neurology. 



upon this subject, which is to comprise a discussion of the conditions 

 in Mollusca and Verteorata, together with a critical consideration of 

 the views of others. This may be awaited wi'h interest and with it 

 the present article can be more satisfactorily judged. 



The original observations in support of the views entertained oc- 

 cupy the bulk of the paper and are presented in five sections dealing 

 with (a) the neurofibrilllse, (b) the nerve and neuroliga cells of the 

 Hirudinea, (c) the ganglion Cflls (his usage), (d) anastomoses be- 

 tween ganglion cells in the central and peripheral systems, (e) rela- 

 tion of the neurofibrillas to the cells at the peripheral end of the fiber. 



In conclusion a discussion of the methods employed is given. 

 The chrome-silver impregnation methods were found altogether inade- 

 quate; the methylene blue methods, gold chloride methods and a spec- 

 ial haematoxylin stain were those employed to stain the fibrillae. In the 

 manner of using all three, however, special modifications were found 

 necessary which are set forth in detail. b. f. kingsburv. 



Cortical Lesions after Thyroid Poisoning.^ 



Experiments were make with thyroid feeding of insane patients 

 and of mice and Guinea-pigs. In the case of the lower animals the 

 feeding was continued until death ensued. The autopsy showed con- 

 gestion of all the viscera, but no demonstrable lesions other than this. 

 The cortical cells seemed perfectly normal, with none of the varicose 

 and atrophied dendrites found in poisoning by alcohol etc. Dr. Berk- 

 ley concludes : 



*' It is obvious from these results that the death of the various 

 animals was induced by an entirely different kind of intoxication than 

 that causing the lesions of the nerve elements in ricin and alcohol 

 toxaemias, and it is therefore a poison that does not induce degenera- 

 tive alterations in the sheaths of the arteries, and the consequent dis- 

 turbance of the nutritive supply, followed by pronounced changes in 

 the neurons, dependent to a certain degree upon the intensity of the 

 vascular lesions; but acts upon the general system in an entirely dif- 

 ferent manner, and is essentially more subtle in its effects upon the 

 nerve tissues, corresponding more to the action of a group of chemi- 

 cal poisons that leave no trace of their effect after death upon the 



1 Henry J. Berkley. Studies on the Lesions Induced by the Action of 

 Certain Poisons on the Cortical Nerve Cell. Study VII. Poisoning with Pre- 

 parations of the Thyroid Gland. Bull. Johns Hopkins Hospital, VIII, 76, 

 July, 1897. 



