INTRODUCTION. XXX111 



the spinous processes, and the depression in the supe- 

 rior posterior part of the neck. The Brain and Spinal 

 Marrow, as belonging to animal life, consist of two 

 halves, presenting corresponding arrangements in the 

 development of cavities and prominences, and so on, 

 and in sending similar nerves to the organs of locomo- 

 tion and of voice. 



The organs of organic life are marked, on the contra- 

 ry, by the character of striking dissimilitude in their 

 two halves, as manifested in the liver, the spleen, the 

 stomach, the intestines, the heart, and the great vessels 

 belonging to it. There are, however, some organs of 

 organic life in which the difference is less prominent, 

 as the lungs of the two sides, the pulmonary arteries, 

 the veins, the trachea, the kidneys, the capsulse renales, 

 and the salivary glands. 



From what has been said, we are, perhaps, prepared 

 to admit with M. Bichat, that animal life is double; that 

 its phenomena being executed after the same manner on 

 both sides of the body, it is very possible for the actions 

 of one side to be suspended or destroyed while those of 

 the other go on. This, in fact, happens in certain pal- 

 sies, where the sensibility and motion of one side are so 

 completely suspended, that it resembles a vegetable; all 

 relation with exterior objects being cut off, and nothing 

 but the function of nutrition being preserved ; whereas 

 the other side retains all its animal properties. For 

 these reasons Bichat has very quaintly observed that we 

 have a right life and a left life. In organic life, on the 

 contrary, the functions of the two halves of any organ 

 are so allied, that the lesion of one affects the other. 

 The liver, in a disease on one side, has its functions im- 

 paired throughout : it is the same with the intestinal ca- 

 nal, and with the heart. 



Congenital deformities are said to be more frequent in 

 the organs of organic life than in those of animal life. 



