44 THE THORACIC VISCERA, BUCGALOCAVITY. 
what is known as the drouchzal tree. The terminal 
twigs of this system end in the air-sacs or alveoli, little 
membranous bags, in the walls of which the capillaries 
of the pulmonary artery are distributed. 
POO, SSHOLIOM (OFT aE DUCE AL NCAy iia 
Remove the skin from the head. Lay open the 
mouth on one side by cutting through the cheek with a 
pair of scissors, and continuing the cut backward 
across the bone with bone forceps or saw. 
1. The Roof of the Mouth. 
a. dae’ HARD PALATE: formed by ther palatine 
processes of the maxillary and palatine bones. It is 
covered by pigmented mucous membrane which is 
raised into a number of transverse ridges. The soft 
palate is continued backward from this and ends in a 
free notched border. 
b. THe Tonsits are two pinkish-gray eminences 
lying lateral to the soft palate and above the root of 
the tongue. | 
¢. THe Trere. Verify. the dental formula 1. 
c. +, pm. 4, m. 4. | 
2. whe Floor ofthe. Mouth: 
a. THE ToncueE is attached. along the greater 
part of its length to the floor of the mouth. The 
mucous membrane covering the upper surface shows 
three different kinds of papillae: the czrcumvatllate, 
four in number, arranged along two converging lines 
at the root of the tongue; the /ungzform, found 
generally over the dorsal surface and especially thick 
at the tip; the f/zform, which toward the root are 
larger than in front, and end in free notched borders. 
They are thickly scattered over the whole dorsal surface. 
eoleo 
