THE SKNSES. 77 



ganglions^ situated in the neck, in the thorax, and in the abdomen 

 in front of the vertebral column, and tied to each other by com- 

 municating cords ; a multitude of nerves arise from these gang- 

 lions and are spread out in the heart, the lungs, the intestines, the 

 glands and other organs of vegetative life. 



32 These parts of the body which receive their nerves from 

 the ganglionic system are slightly sensible, and the movements 

 which they execute are independent of the WILL. 



33. The principal nerves of sensibility terminate in particular 

 organs, through the medium of which they receive and transmit 

 to the brain, the sensations produced upon us by surrounding 

 objects. These organs are each destined to receive sensations of 

 a certain kind, and are called organs of the senses. 



LFSSON VIII. 



FUNCTIONS OP RELATION Sense of touch Skin 

 Hair Heard Kails Horns Mode of formation Sense oj 

 smell Olfactory apparatus Sense of taste Sense of hearing 

 Jluditory apparatus. 



1. We give the name of Senses to those faculties by the aid of 

 which animals take cognizance of the properties of bodies which 

 surround them. 



2. Bodies may differ from each other in different ways ; in 

 their weight, their hardness, their volume, their temperature, &o. 

 by their odour, their taste, their form, and their color, or by the 

 sounds which they afford. 



3. These various qualities cannot be appreciated by the same 

 organ ; the organ which perceives taste for example, is not sen- 

 sible of the color, or odour of bodies ; therefore, the faculty of 

 experiencing sensations from the influence derived from each one 

 of these different kinds of the properties of external objects, is 

 the attribute of a particular organ. 



32. Do the movements of those parts of the body supplied with nervea 

 from the ganglionic system, depend upon the influence of the WILL? Are 

 the (>;irts thus supplied very sensible? 



33. How do the principal nerves of sensibility terminate? 



1. What arc the senses ? 



2. How do bodies differ from each other? 



3. I- any one organ capable of appreciating all the properties of bodies* 



