EFFECT OF ACTIVITY ON NERVE CELLS 349 



Sparrows 



Experiment 2. A male sparrow was shot and instantly killed with a 

 rifle ball at 6 a.m. The brain, cord, and brachial and dorsal ganglia 

 were removed one-half hour later. These were placed in Held's fluid 

 and in 10 per cent formalin. 



Fatigue bird. A male sparrow that had been flying about all day 

 was shot, and the brain, cord, brachial and dorsal ganglia removed 

 one-half hour later, and placed in Held's fluid and 10 per cent formalin. 



Microscopic study. Brachial ganglia — one-twelfth objective, no. 2 

 ocular, Leitz. The cell architecture is distinct in both the fatigue and 

 control specimens. Sections stained with Held's method show the 

 cell bodies stained diffusely pink with distinct Xissl gi-anules stained 

 tlark blue. There is no difference as regards depth of stain of either 

 cell bodies or the amount and size or depth in staining of the Xissl 

 h)odies. No cells in either section showed any crenation of the nuclear 

 membrane such as described by Hodge. Some cells show excentric 

 nuclei and nucleoli, but by actual count this occurrence is just as com- 

 mon in the control specimen. Examination of the anterior horn cells 

 of the spinal cord in the region of the cervical enlargement as well as 

 the examination of the Purkinje cells of the cerebellum show no varia- 

 tion from the control morning specimens with respect to size of cells 

 and nucleus' or in the morphological markings. 



Pigcous 



Experiment 3. For this exjieriment pigeons were selected which were 

 in the daily hal)it of making long flights, sometunes remaining on the 

 wing for over an hour at a time. One of these pigeons was killed just 

 at dusk, and as a control, one approximately of the same age was 

 killed from the same flock at six o'clock the following morning. For 

 study the entire brain was removed as well as the brachial ganglia and 

 sections from the spinal cord in the region of the brachial and lumbar 

 enlargements. 



Microscopic study. Brachial ganglia. The evening (fatigue cells) 

 show no crenation, no central chromatolysis, and there is no apparent 

 difference in the size or distrilnition of the granules from the controls. 

 ]\Ieasurement of a large number of cells show that the differences in 

 size of the cell bodies or nuclei in the fatigue and control specimens fall 

 within the hmit of "variation." 



Anterior horn cells. Brachial cord. No difference in any respect 

 could be detected between control and fatigue specimens. 



Cerebellum. A large number of the cells were studied from both the 

 evening and morning pigeons, but no constant variation in morpho- 

 logical marldngs could be detected. 



