THE STRUCTURE AND GENERAL CHARACTER OF PIGEONS. 7 



structure of a wing than the perfect gradation in strength and stiffness, as well 

 as in modification of form, which marks the series from the first of the primary 

 quills to the last and feehlest of the tertiaries. Now, the sharpness or roundness 

 of a wing at the tip depends on the position which is given to the longest primary 

 quill. If the first, or even the second primary is the longest, and all that follow 

 are considerably shorter, the wing is necessarily a pointed wing, because the tip 

 of a single quill forms the end ; but if the third or fourth primary quills are the 

 longest, and the next again are very little shorter, the wing becomes a round- 

 ended wing. The common rook and all the crows are examples of this. The 

 peregrine falcon, the common swallow, and all birds of very powerful flight, have 

 been provided with the sharp-pointed structure." 



FIG. III. — STET.NUM OF THE PIGEON. 



The mechanism by which the wing is moved has now to be described. It 

 consists of the mass of muscles on the front of the chest. The sternum, or 

 breast-bone of the pigeon, Figure III., has an exceedingly deep keel, a, serving for 



FIG. IV. — MUSCLES OF THE WING OF THE PIGEON. 



the attachment of the powerful muscles which form the great mass of flesh on 

 the breast. These muscles, as shown in Figure IV., pass from the keel of the 



