THE r UNCTIONS OF LIFK. 31 



merely passive, and the sport of every contingent 

 agency, would have been not merely useless, but 

 even baneful endowments. The same beneficent 

 power, which has conferred these gifts, has con- 

 joined that of voluntar^^ motion, by which the 

 animal may not only obtain possession of such 

 objects as minister to its gratification, and reject 

 those which are useless or hurtful, but may also 

 move from place to place, and enlarge the sphere 

 of its perceptions and of its power. The same 

 mass of nervous substance which, under the name 

 of brain, we have recognised as the organ of sen- 

 sation, is also, as will afterwards be shown, the 

 organ of volition ; and the medium, by which the 

 commands of the will are transmitted from the 

 brain to the mechanical apparatus employed for 

 motion, is again certain filaments of nerves ; but 

 these nervous filaments are distinct from those 

 which are subservient to sensation. 



Next in importance, then, to the organs of sensa- 

 tion and perception, are those of Voluntary Motion. 

 They comprise two kinds of objects ; first, the 

 establishment of a certain mechanism, having the 

 cohesion, the strength, and the mobility requisite 

 for the different actions which the animal is to per- 

 form : and, secondly, the provision of a power, or 

 agent, which shall be capable of supplying the 

 mechanical force for setting this machinery in 

 motion. With these objects must be combined 

 various subsidiary arrangements relating to the 

 connexions, the support, the protection, and other 

 mechanical conditions of the organs of the body. 

 It will be convenient to comprehend these under 

 one general head, considering them as composin 



or 



