THE TISSUES 



11 



Fio. 1. 



A. A diagrammatic section of the human body taken vertically 

 through the median plane. C.S. the cerebni-spinal nervous system; 

 N, the cavity of the nose ; ^f, that of the mouth ; Al. Al. the alimentary 

 canal represented as a simple straight tube ; H, the heart ; O, the dia- 

 phragm ; Sy, the sympathetic ganglia. 



B. A transverse vertical section of the head taken along the line a b ; 

 letters as before 



C. A transverse section taken along the line c d ; letters as before. 



