28 THE STORY OF THE BIRDS 



the ridge of the bill (assumed by both sexes 

 during the breeding season), by the American 

 White Pelican, this peculiar excrescence strewing 

 the breeding ground of these birds literally in 

 bushels; and lastly the curious annual moult 

 which the bills of some of the Auks undergo 

 as well as the acquisition and shedding of the 

 horny or fleshy growths above the eyes and 

 round the gape. Our own familiar Puffin 

 furnishes a most interesting instance of this 

 phenomenon. Some very interesting details of 

 this peculiar form of moulting amongst the 

 Alcidae are published by Dr. Stejneger in Bul- 

 letin No. 29 of the United States National 

 Museum. 



We will now proceed to a brief consideration 

 of the most salient characteristics of the skeleton 

 and internal structure of birds. Of course in 

 a work of the present scope it is not only im- 

 possible but unnecessary to enter into any 

 great detail of avine anatomy. The student 

 must seek such information in special works, 

 one of the most useful being Professor Newton's 

 Dictionary of Birds, Dr. Gadow's contributions 

 to which upon this subject being singularly 

 full and original. To these contributions we 

 are largely indebted for the following particulars 



