140 THE INFANCY OF ANIMALS 



scheme, is the palatine. In the emu (Fig. A) this is a 

 roughly triangular plate (Pa), the base of which is applied 

 in part to the foot of the vomer, and in part to the 

 outer border of the pterygoid, as may be seen in the plate. 

 Now compare this with the palate of the South American 

 ostrich or rhea (Fig. C). 



Here it will be noticed the vomer is reduced in size, 

 the palatines have moved inwards toward the middle 

 line, beneath the anterior ends of the pterygoids, and 

 towards one another. In both, emu and rhea, it should 

 further be noticed, for the better comprehension of our 

 story, that the bones known as the palatine processes (Mx), 

 or ingrowths of the maxillse, are very large. In the skull 

 of the tinamou, also a South American bird, and un- 

 doubtedly related to the rhea, we get a still further re- 

 duction of the vomer, while the palatines and pterygoids 

 have become relatively longer, and more rod-shaped. 



Very well. Now compare these three palates with those 

 of the guU (Fig. E) and the common fowl (Fig. D). In the 

 guU, it will be seen, the vomer is stiU further reduced, and, 

 what is more remarkable, is now no longer in touch with 

 the pterygoids, but is borne by the palatines (Pa), which 

 have greatly increased in length, and have met one another 

 in the middle line. The pterygoids, it will be noticed, 

 are slender rods articulating by a cup-and-ball joint 

 with the ends of the closely apposed palatines, while the 

 palatine processes of the maxiUs, to which attention 

 has just been drawn, are extremely reduced. 



Pass from this to the palate of the fowl. This presents 



the same general features as are seen in the guU, but the 



vomer is still further reduced, and is commonly absent 



altogether. If this palate be compared with that of the 



.emu, with which we started, the differences between 



