944 



Rachitis. 



shallow groove and to a sliortoning- of the transverse diameter 

 of the tliorax. The inward bend of the ribs canses the sternum 

 to recede from the vertebral column, while its borders are ap- 

 proximated, so that the sternum forms an acute angle or pro- 

 trudes (chickenbreast, pectus gallinaceum, s. carinatum). 

 When the animals lie down much, the antero-posterior diameter 

 of the thorax is diminished (Fig. 161), because its anterior 

 wall Avhicli rests on the ground is forced inward. In fowls 

 the sternum shows in such cases a single and often a double 

 inward bend (Ziirn). The limited motility of the thorax is 

 apt to cause the development of a lironchial catarrh or of 

 catarrhal pneumonia. 



Fiff. 162. Rachitis in a lamb. 



In the pelvis the acetabulum is pressed upward and inward 

 by the heads of the femurs, while the symphysis is forced down- 

 ward and forward; in consequence the pelvis is narrow trans- 

 versely, as is already indicated by the position of the hind 

 feet which are turned inward. 



The vertebral column presents various deformities (hence 

 the name rachitis, viz., .f^x'^^vertebral column). It is curved 

 either laterally (scoliosis), or upward (k3^phosis), or downward, 

 (lordosis). In most cases tiiere are two or several antagonistic 



