~— 
INHERITANCE OF COAT-COLOR IN CATS Soll 
‘black spots’ are uniform black. The same condition obtains 
in the case of maltese dilution, but the contrast in the bands is 
not as obvious and there is general reduction in the amount of 
yellow pigment. 
Uniformity or lack of banding in yellow cats is apparently 
due, as has been pointed out to me by Dr. Sewall Wright, to some 
other condition than the lack of the agouti factor. As regards 
the existence of such cats, Mrs.- Leslie Williams (’08) writes: 
“The self-orange Persian is more of an ideal than a reality, for 
it is actually a red tabby without the tabby markings, and at 
present it is a case of ‘more or less,’ the upshot being that the 
least marked cat in the class takes the prize.”’ 
Silvering is a general reduction in the amount of yellow pig- 
ment. The straw bands of tabbies then become white. Figure 
A shows a silver-striped tabby skin. Black stripes alternate 
with white. In the skin shown in figure B, on the other hand, 
there is a considerable amount of yellow pigment. <A striped 
tabby (9) brought into the laboratory pregnant had lighter 
bands of a decidedly reddish color. This apparently represents 
the opposite extreme of variation from silvering. Intense black 
stripes alternated with rusty red. She gave birth (22) to three 
male kittens—one striped with black and red; one blotched with 
black and red, and one striped with black and straw color. Here, 
then, is an indication that the extreme reddish tone is hereditary. 
For an understanding of banding we may first consider figure 
B. The skin shown here is from a striped tabby male (7.2) 
forty-two days old. “It may be seen that the bands run longi- 
tudinally along the back and are most easily seen near the mid- 
dorsal line posteriorly. On the sides the bands are transverse 
and tend to be broken into spots. We may think of this condi- 
tion as having been produced by longitudinal and transverse 
waves of pigment-forming metabolic activity. The longitudinal 
waves form transverse bands. The areas of greatest activity 
form orange bands in yellow cats, while in tabbies these bands are 
black. The areas of less activity form, of course, the lighter 
bands. The transverse waves appear to originate at the mid- 
dorsal line. They form longitudinal bands on the back. As 
