2l8 



GENERAL ORNITHOLOGY 



PART II 



not meeting each other. They are wanting in Struthio, Bhea, 

 Apteryx, and some Psittacidm. Besides curving toward each other, 



the clavicles have usually a 

 fore-and-aft curvature, con- 

 vex forward. In general, 

 the strength of the clavicles, 

 the firmness of their connec- 

 tions, and the openness of the 

 V or U, are indications of 

 the volitorial or natatorial 

 power of the wings. The 

 end of the furculum is hol- 

 lowed for a fold of the wind- 

 pipe in the crested pintado. 



Fro. 60. — Pelvis of a heron (Ardea herodias), nat. 



4. THE PELVIC ARCH 



The Pelvis (Lat. pelvis, a 

 basin, Fig. 60) is that pos- 

 terior part of the trunk 

 which receives the urogeni- 

 tal, and lower portion of the 

 digestive, viscera. It consists 

 of the sacrarium on the 

 middle dorsal line, flanked 

 on each side by the bones of 

 the pelvic arch, which sup- 

 ports the hind limb. In ver- 

 tebrates generally the pelvic 

 basin is completed on the 

 ventral aspect by union {sym- 

 physis; Gr. o-vv, sun, together; 

 <^ijcrts, growth) of the bones 

 from opposite sides. Except- 

 ing only Struthio, which has 

 a pubic symphysis ; and Bhea, 

 which has an ischiac sym- 



size, viewed from below; from nature by Dr. K. W. v • ■ 4. t. i j-i, ^nn-nol 

 Shufeklt, U.S.A. dl, clorsolumbar vertebra to and pnySlS ]USt DelOW tne sacrai 

 including the last one, sc ; below sc, for the extent of 

 the large black spaces (opposite the arrow) are the 

 true sacral vertebrte; us, urosacral vertebrjfi (op- 

 posite the five oval black spaces ; II, ilium ; Is, 

 ischium ; P, pubis ; ob, obturator foramen. The 

 arrow flies into the acetabulum. 



vertebrae, the pelvis of 

 bird is entirely open below 

 and behind ; each pelvic 

 arch ankylosing firmly with 

 the sacral vertebrae to form a roof over the viscera above 

 named. This sacro- iliac ankylosis is commonly coextensive 

 with the confluence of the many vertebrae which make the 



