324 THE REASON WHY : 



Thou cold-blooded slave, 



Hast thou not spoke like thunder on my side? 



Beene sworne my soldier, * * 



And dost thou now fall over to my foes ? &quot; SHAKSPERK. 



1034. Why are toads enabled to live embedded in rock 

 or stone ? 



Because their skins are capable of effecting the necessary change* 

 in the system when the function of the lungs is altogether ar 

 rested ; and, requiring an inconceivably small portion of air, they 

 are enabled to live by the supply which penetrates the pores of 

 the material in which they are embedded. 



MISCELLANEOUS. 



1035. Wliy have most reptiles a hind of moveable lid at the 

 iperture of their nasal organs ? 



Reptiles are thus provided, so that when they are under water, 

 the organ of smell may be exercised or protected as circumstances 

 may require. The proper vehicle of the impression of smell in 

 reptiles is air ; and this they draw through their nasal cavities 

 durirg inspiration, effecting the operation by depressing their 

 lingual bone, and thus enlarging the cavity of the mouth. 



1036. WTiy can reptiles abstain for an extraordinary length 

 of time from food and drink ? 



Because the languid circulation of their blood, their rare secre 

 tions, low temperature, and scaly and impermeable envelope, 

 render their losses by evaporation from the skin very incon 

 siderable ; so that the frequent supplies which are wanted in 

 other animals, to compensate for the incessant waste, are not 

 required for reptiles. 



1037. Why are reptiles termed cold-blooded? 



Because they do not produce enough heat to have a temperature 

 sensibly higher than that of the surrounding air. 



The whole of their body is heated qr cooled at the same time ai 



