42 



Diseases of Poultry 



vertebrae of which the first, called the atlas, is the 

 smallest. The vertebrae of the back (6) number seven, 

 but they are usually nearly completely grown together 



into one single mass 

 of bone. To these 

 vertebrae of the back 

 (called the thoracic 

 vertebrae) are at- 

 tached the seven 

 pairs of ribs (7). 



The lumbar verte- 

 brae, of which only 

 one or two remain, 

 are in old birds 

 /s <# grown together with 

 the sacral vertebrae 

 (17). Behind the 

 sacral vertebrae come 

 the caudal (18), which 

 support the struc- 

 ture known, rather 

 colloquially, as the 

 " pope's nose." 

 There are six caudal 

 vertebrae. 



The yelvis consists 

 of three bones fused 

 together : the ilium 



Fig. 6. — Skeleton of cock {Gallus sp.). For (19), the ischium 

 explanation of figures see text. (After /nrw j j.u z • 



Diirisen.) (20), and the pubis 



(21). 



The breastbone (8) bears a high and sharp bony plate, 

 the keel, to which the breast muscles are attached. The 

 wings are supported by the pectoral or shoulder girdle of 



