EFFECT OF ACTIVITY ON NERVE CELLS 355 



taneoiis area of the lower back just after beginning perfusion with 

 normal salt solution and by adding to the perfusion solution. The 

 heart continued beating throughout the experiment. The strychnine 

 caused violent tetanic contractions at first, which later gave place to 

 continued fibrillary contraction. This served as an indication of the 

 condition of irritability of the spinal cord cells. To prevent direct 

 action of the strychnine on the nerve endings in the gastrocnemius 

 muscle, the femoral arterj- was tied off. This muscle continued in a 

 state of irritability for several hours. The experiments carried out by 

 this method were continued for a length of time varying from two to 

 ten hours. Controls were used, treated in the same manner, except 

 for the strychnine injections. The subsequent treatment of the nerve 

 material (sections of the spinal cord and from the thoracic and lumbar 

 regions) was identical. There is a .striking change in both the control 

 and treated cells, which had been perfused for a long period. Many 

 cells as well as nuclei are swollen beyontl the normal size, owing, doubt- 

 less, to a .simple turgescence caused by a flooding of the circulatory 

 system with the salt solution, and the staining reaction is diffuse. 

 There are, however, no differences in morphological characters between 

 the cells of the strj-chnine stinmlated and the control cells of the spinal 

 cord. 



Shock {anaemia) 



Experiment 15. A four kilogram dog was given morphine and bled 

 from the jugular vein; 20() cc. were removed, following which the dog 

 remained semi-comatose for five hours. At the end of this time lie 

 was killed along with a control dog of four and a half kilograms weight. 

 ]\Iaterial was taken from the cruciate gyrus and cerebellar cortex, fixed 

 in 10 per cent formalin, and stained with polychrome methylene l)lue. 

 Examination with the microscope revealed no tlifference in the char- 

 acter of the nerve cells in the shock animal as compared with the 

 control. 



DlSCrSSIOX OF RESULTS 



It luxs long; been known that prolonged activity of mucous 

 gland cells results in cliaracteristic liistological changes in these 

 cells, owing to the disappearance from the cell of certain granules 

 (zymogen granules). This granular material is evidently used 

 to make organic material of the secretion. It was doubtless on 

 the basis of such observations that certain physiologists were 

 led to seek for similar alterations in tlie highly specialized nerve 

 cell following functional acti\-ity. ]Many of the investigations of 

 these physiologists were confined to one or two experiments, the 

 material was often not sufficiently controlled by normal tissue 



