THE CEREBRUM 211 



shows very little permanent effect. When shock has passed 

 off, the animal draws up its legs, erects its head, and assumes 

 the characteristic resting position of a normal frog. When 

 placed on its back it quickly resumes the normal posture. If 

 thrown into water it swims to a solid support and crawls out. 

 Every time its flanks are stroked it will croak with almost 

 fatal regularity. It jumps when stimulated and avoids obstacles 

 placed in its way, showing that its visual reflexes are intact. 

 It is said that more complicated reactions, depending upon 

 the memory of past experiences, or the instincts, are absent or 

 imperfect. 



Removal of the cerebrum in pigeons throws the nervous, 

 active animal into a stupid, lethargic condition. It sits in a 

 drowsy attitude with its head drawn in, eyes closed, and feathers 

 slightly erected. The animal maintains a perfect equilibrium 

 upon a perch, and flies well when thrown into the air. With 

 care and feeding it remains alive indefinitely. If allowed to 

 starve it becomes restless from the effects of hunger, pecks 

 aimlessly at the ground, not being able to actually seize a 

 separate grain and swallow it. The reactions of the animal 

 are more direct and predictable. When placed on a hot plate, 

 it will, for a time, lift one foot after the other, and finally squat, 

 but not fly. When dozing, a loud noise awakens it, but it 

 exhibits no sign of fear. 



In dogs the removal of the cerebrum is more difficult, and 

 if performed at one operation leads to a rapid death. Goltz's 

 dog, in which the brain was washed away in several successive 

 stages, with a stream of saline, lived for a year and a half, 

 when it was killed. The postmortem examination showed that 

 all of the cortex had been removed except a small portion of the 

 temporal lobe, which, being without connection with the rest 

 of the brain, was functionless. A large portion of the corpora 

 striata, thalami, and some of the midbrain had been removed. 

 After the immediate paralysis had disappeared the animal 

 moved easily, and showed a tendency to keep moving. There 

 was no permanent paralysis of voluntary movements. If a 

 painful stimulus was applied to the flank, he would growl or 

 bark, turn his head to the place stimulated, but would not bite. 

 No caressing would arouse signs of pleasure, and no threatening 

 signs of fear. His memory records for the most part had been 



