AND ANIMAL LIFE. 



lion where it is required, and transmiting sensa- 

 tion when it is necessary. 



CCXL VII. The accurate plates of SCARPA point 

 out the great number of nerves which the heart 

 receives from the sympathetic and par vagum ; 

 and if the distribution of these to an organ is a 

 powerful argument in support of their influence 

 in secretion, it may be asked, what does the heart 

 secrete ? But if they be allowed to give motion 

 and sensibility, it is evident that the function of 

 the organ satisfactorily accounts for the multi- 

 tude of nervous fibrillae. Its constant con- 

 tractions are effected by its nerves of motion, 

 which endow its muscular fibres with a property 

 called irritability, and, unless it possessed this ex- 

 tent of nervous energy, the blood would not be 

 able to maintain its regular action. Secretion 

 and nutrition are accomplished in the vegetable 

 without the assistance of nerves ; and this fact, 

 from the similarity of the functions in both in- 

 stances, naturally leads the mind to conclude 

 that these are the result of laws not directly de- 

 pending on the nervous system. 



CCXLVIII. As we rise in the scale of being, 

 additional and more perfect organs are developed, 

 and the nervous system is also proportionately 

 augmented to meet the demands of these super- 

 added powers. 



CCXLIX. The manner in which narcotics 

 influence the generation of heat, and the secre- 



