290 THE SNAKES OF SOUTH AFRICA. 
THE SALIVARY GLANDS AND TEETH. 
We are provided with incisor or front teeth for biting and 
tearing our food ; and molars for the purpose of carefully grind- 
ing up the food before it is swallowed. True, we have canine 
teeth, with which our primitive ances- 
tors fought their enemies, before they 
evolved the idea of using branches of 
trees as clubs, and stones as weapons. 
The instant food enters the mouth, the 
salivary glands pour out their secretion, 
which is known as saliva. This saliva 
is very important, for it performs a 
work which the stomach is unable to 
do. The saliva has the power of 
changing the starchy parts of the food 
into quite another substance. In fact, 
it partly digests and prepares it for 
another process which will take place 
later in the stomach and bowels. 
It is very important that we should 
chew up our food thoroughly before 
swallowing it. Parents should take 
the greatest possible care of their 
children’s teeth. The teeth should 
be cleaned, and the mouth washed 
every morning, and at bedtime. The 
mouth-wash should contain some anti- 
septic. Opa is one of the best. Three 
or four drops in a wine-glass of water 
is sufficient. Without good teeth, the 
food cannot be properly prepared for 
BiG, 116 The |, Whole digestive’ thestomach. Good teeth and a healthy 
apparatus of a human being. 
It is about 30 feet in length. id’ 
(From Black's Physiology) Stomach are a child’s great asset. 
THE STOMACH. ~ 
When the food is swallowed, it goes down a long tube called 
the gullet or Gsophagus. The instant it enters the stomach, 
the gastric nerves receive a stimulus, and digestion begins. The 
stomach is a large, hollow, muscular bag. Embedded in its 
