HYGIENE OF DIGESTION 241 



431. Classification of mammals according to food : 



432. THOUGHT LESSON. Comparison of Mammals. 



Which of the kinds would probably have quickest digestion ? 

 Slowest ? Which eats food that would spoil if not quickly 

 digested? Which eats food that would keep sound? Is 

 there an appropriate relation between extremities and teeth? 

 Which kind of mammals has closest resemblance to the 

 frugivora? Which kind has least resemblance to the 

 f rugivora ? Why ? 



433. Man's Original Food Resources and how they have 

 been enlarged. Cuvier, Owen, Huxley, and other com- 

 parative anatomists agree that man was originally frugiv- 



1 Body measured from tip of nose to end of backbone. Mammals are the 

 highest vertebrates. The mother nourishes the young with milk. The 

 mammary glands are on the abdomen for all of the kinds of mammals except 

 the fourth. With the frugivora they are on the thorax. 



