QtriKTOCtTBITALISM: IK THE Wiya OF BIRDS. 



227 



reptiles, is that tlie coracoids sliould overlap at their junction 

 with the sternum. This is well marked in some birds, and 

 occurs occasionally among species of Oolumba and in individuals 

 of C livia. In birds generally the coracoids tend to be more 

 and more separated at their sternal articulation. In mo.^t 

 pigeons they either actually meet or are very close together 

 indeed. Among the eutaxic forms they just meet in C and E ; 

 in the others they either do not touch at all or are well 

 separated. 



Angle of Scapula and Coracoid. — This angle varies with the 

 development of certain wing-muscles, and on the whole varies 

 inversely as the power of flight. While it is impossible to lay 

 much stress upon it from the ordinary systematic point of view, 

 it may at least be said that there is a close connection between 

 wide angle and degenerate wings. The angle among pigeons 

 varies considerably ; among the eutaxic forms it is never more 

 than 50 angular degrees, and generally is considerably less. 



Fig. 6. 



I. Columba. II. Phloganas. III. Leiicosarcia. IV. 

 at shoulder-girdle. The coracoid is dotted. CL 

 coracoid. 8c. Scapula. 



Corvus. — Articulation 

 Clavicle. F.C. Pro- 



Frocoracoid Process. — Fiirbringer has investigated the pro- 

 coracoid process and the relations of the scapula, coracoid, and 

 clavicle with the greatest care, and has drawn a number of im- 

 portant conclusions from their conditions. It may be said 

 generally that a large procoracoid articulating with the clavicle 

 and a separation of clavicle and scapula are comparatively simple ; 



17* 



