ELEOTUICAI.LY 8TIMULATP:i) OANHf.ION CELLS. 5 



Kiiliue,' ill the course of his other fstudies, notes a 

 fact which bears directly upon the present subject. 

 This is a disarrangement and a shrinking together of 

 the axis-cylinder fibrils of the nerves in the nictitating 

 membrane of a f i"og, due to ten minutes unipolar stim- 

 ulation of the nerve root within the skull. Also 

 vacuoles make their appearance among the fibrils. 



The only paper devoted to the exact problem under 

 consideration has come out within the last month. 

 The author states the exact question : " Is the activity 

 of the central nervous system accompanied by changes 

 recognizable with the microscope?'" He proceeds to 

 answer the question under the idea that staining 

 reveals much finer differences than changes of form. 

 This determines his method, which consists in choos- 

 ing two frogs of the same weight and sex, the one to 

 be experimented with, the other for control. He then 

 proceeds to stimulate by induction shocks the eighth 

 nerve of one for one hour, keeping the control frog as 

 quiet as possible during the same time. The spinal 

 cords of both are hardened in corrosive sublimate 

 solution and alcohol, and sections made through both 

 cords opposite the origin of the eighth nerve. The 

 sections are stained on the slide with haematoxylin, 

 nigrosin, eosin, and safranin, the Gaule combination, 

 in the order named. In some cases, the author 

 states, sections of each cord are treated on the same 

 slide. It is significant that here too the interest 

 centers about the nuclei. These, by a difference of 

 staining, fall into two categories, the red and the blue ; 



' Neue Untersurfhungen iiber motorische Nervenendigung. Kiihne. 

 Zeitschrift fiir Biologie, 1887, p. 56, Table D, Fig. 64. 



■Wird der thiitige Zustand des Centralnervensystems von micro- 

 scopisch wahrzunehmenden Veriinderungen begleitet? Bohdan 

 Korybutt-Daszkiewicz. Archiv fiir mik. Anat. 18S9, p. 51. 



