io8 



The Bird 



spinal chord passes into the brain, and below it is a 

 small knob, which in the living bird fitted into the first 

 vertebra of the neck. It is a very tiny projection of 

 bone, but fraught with significance: for if we look at 

 the skulls of a frog, a mouse, a cat, a horse or a man, we 

 will see that the head hinges upon two bony projections, 

 but in all birds and reptiles there is but one, — a very 



Fig. 84. — Rear views of bird (Hornbill) and mammal (Yaguarondi) skulls. Notice 

 single facet (occipital condyle) in the bird and two in the manmial, connecting 

 skull with the neck-bones. 



plain hint of the relationship of these two Classes, so dif- 

 ferent in external appearance. The head thus pivoting 

 upon a single point, the bird can turn its head much 

 farther around than if there were two points of attach- 

 ment. Before we leave this great opening, as the scien- 

 tists call it when they speak of it as the foramen magnum, 

 it may be worth while to mention the remarkably con- 

 stant position of the bones around it. Whether these 

 are all separate, or solidly fused into one, we may always 



