562 P. W. WHITING 
On the other hand, variations in the ticking factors and in the 
banding or pattern factors occur both in wild and in domestic 
mammals. Such variations in the domestic cat produce color 
patterns closely similar to numerous wild species. Variations 
from red to silver occur in wild cats. The tiger has a high de- 
gree of red with a moderate amount of ticking. Thus the pat- 
tern is very well marked. In the lion and the puma as well as 
in the jungle cat and others, the red is reduced to yellow while 
the ticking is very intense. Hence the pattern appears only in 
young animals and is obliterated by the increase of ticking inci- 
dent with maturity. Other cats like the ounce or snow-leopard 
and Pallas’ cat represent an extreme reduction of yellow pigment 
comparable with silvering in domestic tabbies. Loss of agouti 
producing black varieties of leopards and others are well known. 
Small species of African and Asiatic cats vary so in color that 
much confusion has resulted in taxonomy. All of this diversity 
may apparently be reduced to variations in ticking, in banding, 
and in the red-silver series. Spots, I believe, are produced by 
crossing of longitudinal and transverse waves of pigment-form- 
ing metabolic activity. In these respects the domestic cat tends 
to ‘mimic’ its wild relatives, but whether the variations have 
originated by crossing or by mutation is an open question. 
IV. THE SUMMARY 
The inheritance of color variations in the domestic cat has 
been investigated at the Zoological Laboratory of the University 
of Pennsylvania. 
Maltese dilution segregates distinctly from intense color and 
is probably recessive. 
Solid white is a simple and complete dominant over color. 
White-spotting is very irregular in inheritance. There is partial 
correlation between dominant white, blue eyes, and deafness. 
has shown that mutations have occurred in Drosophila virilis (species B) produc- 
ing characters similar to mutant characters in D. ampelophila. Such varia- 
tions are inherited according to a similar mechanism and show comparable link- 
age relationships. I am of the opinion that resemblances in the colors and 
patterns of different mammals are often due to such genetic homology, 
