212 The Bird 



condor which was playfully galloping around the fright- 

 ened bird. 



Millions of years ago, in the geological period of time 

 known as the Jurassic, there existed gigantic sea-lizards, 

 which we call Ichthyosauri. All we know of them we 

 have learned by stud}^ of their fossil bones which, through 

 the ages, have been preserved in rocks. One notable 



Fig. 153. — Brown Thra.sher with ej-es wide open. 



thing about them was the great size of their eyes — meas- 

 uring as much as twelve and fourteen inches across. 

 These orbits were surrounded by a series of bonj' plates, 

 and in certain birds of to-day we find a similar circle of 

 small overlapping bones. 



To make the simile between a camera and an eye hold 

 good, we must show that the latter is provided with a 



