Eye. 95 



NASAL OEGAN. 



The nasal organ is prepared in the same manner as 

 the internal ear, and can be conveniently removed and 

 hardened with it. Transverse sections should be made 

 through the anterior part to show the membrane of the 

 respiratory part and transverse sections further back, 

 and show the olfactory membrane with its peculiar 

 epithelium. 



The septum of the nose should also be carefully re- 

 moved from a specimen, and longitudinal sections made 

 of it : if these sections are very carefully handled, they 

 will show both the respiratory and olfactory epithelium 

 very well. They are best stained in logwood and 

 mounted in Canada balsam. 



EYE. 



The eye may be hardened in chromic acid mixture 

 or in Muller's fluid. It must be removed without 

 squeezing, and a few incisions made, it can then be 

 hardened whole. When sufficiently hard, divide the 

 eye longitudinally with a sharp razor. 



RETINA. 



The retina will be found lying on the inside of the 

 posterior part of the eye, from which it may be gently 

 detached by a spear-shaped knife, it may be then frozen 

 and sections cut ; it is better, however, to stain it first, 

 as thin sections are so transparent it is difficult to see 

 them. When prepared in Muller's fluid the retina is 



