312 THE HUMAN BODY. 



does one meet the business man, so absorbed in money- 

 getting that he has lost all power of appreciating any but 

 the lower sensuous pleasures; the intellectual joys of art, 

 science, and literature have no charm for him; he is a mere 

 money-making machine. One, also, not unfrequently 

 meets the scientific man with no appreciation of art or 

 literature; and literary men utterly incapable of sympathy 

 with science. A good collegiate education in early life, 

 on a broad basis of mathematics, literature, and natural 

 science, is the best security against such deformed mental 

 growth. 



APPENDIX TO CHAPTER XX. 



1. Place a frog on the table: note that it sits up and breathes 

 (as shown by the movements of its throat), and either stays still or 

 jumps around as it pleases; i.e., it has a Will of Us own, and its actions 

 cannot be predicted. 



2. Etherize two frogs (note, p. 68), removing them from the ether- 

 ized water the moment they become insensible. With strong sharp 

 scissors cut off from one frog (a) all the head in front of the anterior 

 margins of the tympanic membranes: in the other frog (b) remove 

 the head along a line joining the posterior borders of the tympanic 

 membranes. Place both frogs aside on a dish containing a little 

 water for half an hour. The quantity of water should be such that 

 while keeping the frogs moist it will not reach to the wounds. 



3. The frog (a) which has lost its cerebral hemispheres, but re- 

 tained its mid brain, cerebellum, and medulla oblongata, will be 

 found after the above-stated time sitting up in a natural position, and 

 breathing. Left to itself it will, however, never walk or jump; it 

 shows no sign of possessing a will. Its heart continues to beat and 

 its respiratory muscles to contract, but left alone it stays where it is. 

 Turned upon its back it will regain its feet; and put into water it 

 will swim: its muscles, and the nerves controlling them, are, there- 

 fore, quite able to act. The animal stays still not because the parts of 

 its body necessary to produce movements are injured, but because it 

 can no longer will a movement. Such a frog shows very well the de- 

 pendence of volition upon the presence of the cerebral hemispheres. 



