22 PERSONAL APPEARANCES IN HEALTH AND DISEASE. 



throughout it, and the textures underlying it, of blood- 

 vessels full of blood ; this has a great influence on the 

 shape as seen by the shrivelled aspect of a part which 

 is deprived of blood from any cause, e.g. cold, which 

 causes contraction of the small arteries, and lessens the 

 supply of blood to the part. 



The general form is dependent on the due relation of 

 all these parts, and modification in either will lead to pro- 

 portionate change in shape of the body. The shape of 

 FlG 4 * the head, as a whole, is deter- 



mined by the form of the skull, 

 as is well exemplified in the 

 negro (Fig. 4), where the pro- 

 tuberant and prominent lips are 

 attached to the projecting upper 

 jaw-bones - the prognathous 

 form of skull. 



It may be observed that there 

 is a perfect bilateral symmetry 

 in the whole body a symmetry which is not only apparent 

 on the exterior, but obtains in the skeleton, and to a great 

 extent in the disposition of the internal organs. 



We may now rapidly enumerate the leading changes in 

 form undergone by the body at different periods of life. 

 * Skull of negro, showing prognathism. 



