THE NERVOUS SYSTEM AND ORGANS OF SENSE 403 



uninjured in any way, we find that the frog acts spontaneously. It tries to 

 escape when caught. It feels hungry and seeks food. It is capable of 

 voluntary action. It acts like a normal individual. 



Functions of the Cerebrum. In general, the functions of the 

 different parts of the brain in man agree with those functions 

 we have already ob- 

 served in the frog. The 

 cerebrum has to do with 

 conscious activity; that 

 is, thought. It presides 

 over what we call our 

 thoughts, our will, and 

 our sensations. Each 

 part of the area of the 

 outer layer of the cere- 

 brum is given over to 

 some one of the differ- 

 ent functions of speech, 

 hearing, sight, touch, 

 movements of bodily 

 parts. The movement 

 of the smallest part of 



the body has its definite Regions of the head and action of the different 



localized center in the P arts of the bram - 



cerebrum. Experiments have been performed on monkeys, and 

 these, together with observations made on persons who had lost 



the power of move- 

 ment of certain parts 

 of the body, and 

 who, after death, 

 were found to have 

 had diseases localized 

 in certain parts of the 

 cerebrum, have given to as our 

 knowledge on this subject. 



Reflex Actions ; their Meaning. 

 Diagram of the path^ of a simple If through disease or for other 

 nervous reflex action. reasons the cerebrum does not 



