248 maine agricultural experiment station. i914. 



Summary. 



1. Yellow and variations are due to the presence of lipo- 

 chrome pigment in the epidermis, with the absence of melanin 

 pigment. 



2. White results from the lack of pigment. 



3. Blue color obtains when melanin pigment lies in the upper 

 dermis, with the absence of this type of pigment in the epider- 

 mis. 



4. Black and variations depen^ upon the presence of melanin 

 pigment in the epidermis. 



5. Green appears when lipochrome pigment lies in the 

 epidermis, and melanin pigment in the corium only. 



6. All shades, with the exception of red and pink are the 

 result of various combinations of these pigments ; orange-yellow 

 and black-brown. 



