432 ANATOMY AND PHYSIOLOGY OF THE BRAIN; 



between the shoulders. The plumage is smooth and glossy, 

 but is uniformly expanded by a kind of erection of the 

 feathers, so that the body appears somewhat puffed out 

 and larger than natural. Occasionally the bird opens his 

 eyes with a vacant stare, stretching his neck ; perhaps shakes 

 his bill once or twice, or smoothes down the feathers upon 

 Ms shoulders, and then relapses into his former apathetic 

 condition." Common and special sensibility are retained, 

 but the animal is unable to associate the impressions with 

 the ideas of their ordinary causes or sequelae. Thus, the 

 pinching of a foot causes the animal to move uneasily once 

 or twice from side to side, but does not otherwise affect him. 

 A pistol discharged behind his back leads him to open his 

 eyes and turn his head half round, but does not seem to 

 suggest any idea of danger or injury, and he immediately 

 relapses into his condition of quietude. Longet found that 

 by moving a lighted candle before the eyes of the bird, in 

 a dark place, the eyes and head often follow it from side to 

 side, and the eyes are sometimes fixed for several seconds 

 on an object in the quiescent state. 



The power of connecting ideas received from external 

 objects seems entirely lost, and memory does not appear 

 to retain an impression from one moment to another. But 

 a tolerable control is exerted over the voluntary muscles, 

 and if thrown into the air, the creature is still capable of 

 flying. 



The hemispheres, thus, do not seem essential to sensation, 

 or even to some acts of volition, but are especially designed 

 to receive and retain impressions, to associate ideas, to draw 

 conclusions from them, and to preside over those move- 

 ments which require a deliberate act of the mind. 



The physiology of the remaining parts of the brain proper 

 is by no means well understood. The corpus callosum has 



