PERSONAL APPEARANCES IN HEALTH AND DISEASE. 57 



In rickets, the ribs, like the rest of the skeleton, being 

 soft and yielding, offer less resistance to the pressure of 

 the atmosphere than if they were firmly ossified, and are 

 also less able to act as supports to the muscles bearing 

 on them. The lungs being imperfectly filled with air, the 

 chest-wall tends to sink in, and a wide groove is pro- 

 duced on each side of the breast bone from the yielding 

 of the soft ribs, except at the lower part, where the liver, 

 stomach, and spleen, the highest organs in the abdJmen 

 which underlie the diaphragm, or muscular septum be- 

 tween the chest and belly, prevent their falling in. This 

 depression, when marked to a full extent, gives the 

 shape of chest known as the pigeon-breast, the sternum 

 appearing to be thrust forward like the prominent and 

 keeled breast-bone of birds. When from any cause 

 the entrance of air into the lungs is impeded, as, for 

 instance, in consequence of some obstruction to the 

 air passage by enlarged tonsils, the tendency to the 

 formation of the pigeon-breast is greatly increased. 



A deep and broad chest the chest of "inspiratory 

 type " results from enlargement of the lungs, an enlarge- 

 ment which may be due to disease, in which as a result 

 of continued attacks of bronchitis, or>of asthma, or con- 

 tinued exercise of the lungs 'forcing air through narrowed 

 apertures, as in the playing of wind instruments, or in hard 

 manual work, where efforts are constantly made to fix the 



