378 THE OUTGO OF ENERGY 



vertebral column. Connect the front margins of 

 the two tympanic membranes by a transverse in- 

 cision through the skin. This transverse line 

 will pass over the junction of the cerebral lobes 

 with the optic lobes. Strip off the parietal bones 

 with forceps, beginning at the anterior end oppo- 

 site the anterior margin of the orbit. When the 

 cerebral hemispheres are uncovered, they may be 

 removed from before backwards. Avoid injuring 

 the optic lobes. Work rapidly but carefully. If 

 the ether effect diminish before the operation be 

 finished, replace the frog under the glass jar for 

 a few moments. As soon as the hemispheres are 

 removed, sew up the wounds in the skin. 



Note the signs of profound inhibition. 



If the operation be done carefully, the shock 

 will gradually pass away, and the functions possi- 

 ble in the absence of the cerebrum may then be 

 determined. Put the frog aside, moistening his 

 skin occasionally, but not otherwise disturbing 

 him, and prepare a second frog for the experi- 

 ment upon the " croak reflex " (page 379). When 

 this operation is completed, resume the observa- 

 tions on the first frog, while the second frog re- 

 covers from the shock. 



1. Posture, etc. Write down the differences 

 between the frog from which only the cerebral 

 hemispheres have been removed and a frog in 



