DESCRiPTioisr OF Plate 6. 

 Lung of Neciurus macidcdus. 



!Fig. 9. Surface view of elastic fibers over the pulmonary artery. 

 Orcein staining, x 400. 



Eig. 10, The finer network of nerve fibers, showing medullated 

 and non-medullated fibers and nerve cells. Methy- 

 lene blue. X 75. 



