PERSONAL APPEARANCES IN HEALTH AND DISEASE. 69 



Although much of the colour of the body depends 

 upon the blood, and although some of the chief 

 indications of derangement of health may be found in 

 changes of the colour due to blood conditions, yet there 

 is also throughout the body a large quantity of special 

 pigment deposited in different regions. This colouring 

 matter wherever it occurs is brown or black, and is met 

 with in the form of minute particles or granules within 

 the constituent cells which make up the various structures 

 where it is found. Derived as it probably is from the 

 blood-colouring matter, its composition is clearly allied to 

 this substance, only it is even richer in carbon. In some 

 places where it is deposited it subserves definite uses ; 

 but for our present purpose we have only to consider 

 it as affecting the colour of the body, and we are thus 

 limited to its consideration in influencing the colour of 

 the skin, of the hair, and of the eyes, or, more strictly 

 speaking, of the "irides." 



Regarding then, for our present purpose, the skin only 

 as the seat of colour, and leaving for others* to deal with 

 its more important functions as an excretory organ of the 

 body, it will suffice to describe the structure of this 

 integument just so far as is necessary to give a clear 

 conception of the cause of its colouration. 



* For full details as to structure of skin, see work in this series 

 on the Skin. 



