go The Third and Fourth Generation 



factor, which if present determines that the 

 color shall be uniformly spread over the 

 surface. If U is absent the color appears in 

 blotches, separated by white areas. A desig- 

 nates the agouti factor. When this factor is 

 present the color is distributed in a particular 

 way in each hair : the tip is black, then follows 

 a band of yellow, and the base of the hair is gray. 

 The general effect produced is a uniformly gray 

 coat color. I stands for the intensity factor, 

 which if present makes the black or yellow 

 strong. If absent, the black is a diluted black 

 or blue, and the yellow becomes cream. If 

 factors A, B, C, E, U, are present in the cells of 

 an individual, it is a gray, for the agouti hair 

 pattern can develop if C is present with factor B 

 to operate on it. E determines that the color 

 is distributed aU over the body, and U that it is 

 uniform, not interrupted by white patches. 

 But an individual whose cells contain A, B, Y, 

 C, E, U, would also be gray, as would one whose 

 cells contain A, B, C, E, U, I, or A, B, Y, C, E, 

 U, I. Some or all of these factors may be 

 present in double dose, so that AA, B, C, E, U; 



