i86 



The Bird 



oxygen; and the blood taking up and transporting both 

 to every part of the body. 



The normal temperature of our body is about 98^°; 

 if it rose to 106°, we should soon succumb to the burning 

 fever, while the little bird before us is healthy and com- 

 fortable with a temperature of 110° to 112°! 



Fig 137. — Amoeba, greatly magnified. (Courtesy of Dr. G. L. Calkins.) 



The next time you see a wee chickadee, calling con- 

 tentedly and happily while the air makes you shiver 

 from head to foot, think of the hard-shelled frozen in- 

 sects passing down his throat, the icy air entering lungs 

 and air-sacs, and ponder a moment on the wondrous Httle 

 laboratory concealed in his mite of a body; w^hich his 

 wings bear up with so little effort, which his tiny legs sup- 



