The Framework of the Bird 



6 9 



scales, two ringers of each hand were lost, and one from 

 each foot; teeth disappeared; a beak of horn proved 

 best; intelligence increased and the forehead rose high, 

 and behold, a bird! Can we then despise even an Eng- 

 lish Sparrow? 



All these things we have learned from a comparison 

 with creatures other than birds, and we may, without 

 trouble, take one more glimpse into the dim past. Let 

 us go to the hencoop, where for three days the patient 

 biddy has been sitting on her precious eggs. We will 



FIG. 45. Neck vertebrae of an Ostrich, highly complex and bony in structure. 



rob her of one she will not miss it while from it we 

 may learn many wonderful things. Rest the warm egg 

 in a dish of sand, carefully picking away the shell from 

 the upper part. A glance at the tiny embryo lying on 

 the yolk within will show a double series of tiny squares 

 extending down the long diameter of the body. These 

 are the first hints of the spinal column, and if we could 

 follow its further development we would see something 

 of great interest. The squares are now divided up like 

 beads, just as are the bones of our bird's vertebrae; but 

 in reality this first segmentation is a false one. It is sim- 



