EXPERIMENTAL STUDIES ON THE THALAMUS 25 



July 5. 8.00 a.m. Bird fed. Room temperature, 28°. Tempera- 

 ture of bird, 37°. No restlessness during the day; stands sleeping. 



3.00 p.m. Sudden change in the weather. Rain and wind. At- 

 mospheric temperature falls to 22°. 



10.00 p.m. Temperature of bird has fallen to 33°. The bird stands 

 on its feet with difficulty supported by its tail : or bird lies on floor of 

 cage. Unable to perch on my finger. 



Nystagmus of eyes, rotatory and post-rotatory barely detectible when 

 bird is rotated. Nystagmus sometimes uncertain or it may appear 

 after a long latent period. Nystagmus can be seen if the rate of rota- 

 tion is very slow; reactions of the eyes are very slow. Slight claw foot. 

 Head nystagmus (or compensatory movements) very distinct, although 

 the nystagmus of the eye is very sluggish. Respiration slow and deep; 

 12 per minute. 



The toes irritated with a needle. The head is lowered and bird 

 preens the leg or runs its beak over the toes. This was repeated 

 fifty times in succession. Twelve times the bird brought its beak 

 to the exact point of irritation. Movements are rather slow and slug- 

 gish, not quick and vigorous. I use a stronger stimulus to the toes. 

 The foot was raised. 



Increase strength of stimulus. Foot jerked sharply backwards. 



Still stronger irritation (painful). Bird steps backward and turns 

 around. 



This kind of stimulation applied to both feet. Seventy-five times 

 to right foot and then the lowering of the head to the right foot ceased, 

 although the stimulus continued. 



Then repeated the stimulus on the left foot; head promptly brought 

 to the left toes twenty-two times in succession, but not to the right when 

 right was again stimulated. 



July 6. 11.00 a.m. Temperature of bird, 31.5°. Respiration, 12, 

 shallow. Marked claw foot. Bird supports itself by tail; unable to 

 stand without this support; unable to perch on finger. Feathers flat. 

 Renewed irritation of toes with a needle. 



Repeated stimulation a number of times. Only once as the head 

 lowered to the toes, and then very slowly. 



Strong stimulus to toes and foot slowly lifted. 



Movement sluggish. 



Nystagmus: rapid rotation; no quick component; slow rotation; 

 quick component present; both rotatory and post-rotatory. 



By choosing the proper rate of rotation, it is possible to show devia- 

 tion without the quick component; another rate will show both devia- 

 tion and quick component. 



Bird put in incubator at 30°. 



July 6. 9.00 p.m. Temperature of bird 38°. Equilibrium normal; 

 swallows water easily; removed from incubator. 



July 7. 8.00 p.m. Temperature bird, 32°. No feed to-day. 



9.00 p.m. Temperature bird, 32°. 



Slight tendency to claw foot; bird tries to walk in a clumsy fashion; 

 tries to coo in a low difficult gurgle. 



