Lesson V.] 



NATURAL HISTORY. 



together. In order to do this, he examines the structure of the extremities, and the 

 arrangement of the teeth, which, with other peculiarities, enables him to fix each 

 individual in its proper place. 



QUESTIONS. 



61. T. What is the use of examining the 

 general structure of the extremities of 

 animals ? 



P. To enable us to learn something of 

 their habits. 



62. T. How will this give us a clue to 

 their habits ? 



P. Because their extremities are adapted 

 for the mode of life they lead. Thus, 

 the external configuration of the orang- 

 outang of Borneo at once indicates his fit- 

 ness for climbing trees and clinging to 

 their branches : 

 and the general 

 form of the lion 

 denotes greater 

 strength in front 

 than behind ; 

 the thick neck. 

 and broad chest 

 and shoulder*, 

 are well adapted 

 tin the weight of his prey . and his 

 fore-limbs exhibit a beautiful arran. 

 for strength and seizure, the paws being 

 armed with most powerful, hooked, sharp, 



and hard dawn, suited for tearing, and pro- 

 tected by a l>< hanism from 



the paw of a lion, 



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 lhowin K - the I. ..', , > !. 



- tuition with 

 uc. cuwrmg tiictu. 





injured during progression or other mo- 

 tions. By a peculiar arrangement of 

 muscles they are enabled to retract or draw 

 back their claws, the same as a cat does ; 

 so you see that we are enabled at once, by 

 examining the foot of an animal that can 

 retract its claws, to decide that it belongs 

 to a certain class of animals. 



63. T. Explain how the lion is enabled 

 to retract the claws. 



P. You will understand the manner in 

 which they are retracted much better by 

 referring to this diagram, than by a mere 



description. When the retraction takes 

 place, the ends of the two bones (/) are 

 .i pon the ground, between which and 

 the hones, a pad of thickened skin is in- 

 terposed. I cannot explain the itf 

 the projection of the claws better than by 

 drawing my hand forcibly backwards and 

 curving the fingers, and then suddenly 

 throwing it downwards, the arm being 

 horizontal at the time. 



/'.Does not the perfection 

 organs of touch influence us in cln- 

 iltf 



Pig 4. Thtmtcl 

 * I* rtr acted 



K'mlanx. whirli ii K r 

 i't in (i retracted < 



(/) paaact o**r ih up 

 act* with fritow. 



iportad tht laM 



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