LESSON XXV. 

 TASTE AND SMELL. 



A. OBGANS OF TASTE AND SMELL. 



1. Cut off the head of a newt 1 , remove the lower 

 jaw, cut off the nose by an incision carried just 

 in front of the eyes, with a fine pair of scissors 

 remove the roof of the nasal cavities, and 

 place the remainder of the nose in osmic acid 

 1 p.c. for 2 to 24 hours as convenient. Tease 

 out in water a small piece of the mucous mem- 

 brane. Or place the nose in Miiller's fluid for a 

 week, and tease out the mucous membrane in 

 the same fluid or in water. Observe 



a. The cylindrical epithelium cell, its large 

 oval nucleus, its broad, clear, peripheral 

 process, and its branching, faintly granular, 

 central process. 



6. The rod-cell, (olfactory cell) with its spheri- 



1 Instead of this the nasal mucous membrane of a mammal may 

 be taken, it is best to take it with the underlying bone or cartilage 

 attached (cp. p. 30, 22). 



L. 17 



