THE HUMAN BODY AS A MACHINE 



PROBLEM XLI 



A study of man as a vertebrate compared with a 

 frog. 



a. Comparisons 



Observations. 1. Note that the body of man is divided into 

 two distinct regions, head and trunk. Can you find these in 

 the frog? Is the head movable? How does it differ from 

 that of man ? 



2. What is the body covering of the frog ? How does it 

 differ from that of man ? Note. The sliminess of the skin of 

 the frog is due to some cells that pour out mucus. 



Conclusions. 1. Can you think of any use for this secre- 

 tion ? 



2. Why should a frog's head be more flattened than that of 

 man ? 



Observation. - Note the position of the eyes of a frog. How 

 does it differ from the position of the eyes of man ? 



Conclusion. Does a frog need a neck as does man ? Explain. 



Observations. 1. Note the divisions of a fore limb or arm, 

 into upper arm (forearm) and hand. How many fingers on 

 each hand ? 



2. How do the fore limbs of a man differ from those of a 

 frog? 



Conclusion. How do the functions of the hand of a man 

 differ from those of a frog ? 



Observations. 1. Find the thigh, shank, and foot in the hind 

 leg of a frog. 



2. How many toes on each foot ? How do the hind feet 

 differ from the front ones ? 



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