MILLER — COAT COLOR OF MOLES 
163 
THE COAT COLOR OF MOLES 
By Loye Miller 
Castle/ in his studies of color inheritance in various domestic rodents, 
learned that the gray coat of wild rabbits is highly complex in its nature, 
the resultant of joint action of several independent factors, and that 
the various color phases known to the rabbit fancier are but the effect 
of weakening or loss of one or more of these factors. He recognizes 
in the rabbit no less than eight such factors and offers as evidence of 
their presence, the mathematical results obtained in cross breeding. 
Any one who will follow the account of his experiments with some 
measure of care will perforce admit the weight of his conclusions and 
will concede that the methods of analysis by careful pedigreed cross 
breeding approach in accuracy the work of an analytic chemist. 
The eight factors established for the rabbit are as follows: 
1. A color factor, necessary to the formation of nil pigment and 
absent in albinos. 
2. A factor for black. 
3. A factor for brown. 
4. A factor for yellow. 
5. A factor for intensity of color. 
6. A factor for pattern of individual hairs. 
7. A factor for self coloration, i.e., no white spotting. 
8. A factor for extension of dark pigments from extremities of ears 
and feet. 
This formidable array of color factors, each acting as an entity in 
transmission through the generations, can be proven only from the 
record of tremendous numbers of cross matings under absoliite control, 
hence such proof is out of the question in a wild race. However, 
by taking account of seeming parallelism and by making use of the 
occasional sporadic aberrant that comes to the hand of the field natural- 
ist, some pardonable conjecture may be formulated. 
The very interesting account by Patter son^ of a cinnamon phase 
of the roof rat, developing in Travis County, Texas, represents such a 
case. The rat in an animal that can usually be kept in captivity and 
reared in large numbers, so attempts to breed the new cinnamon roof 
^ Castle, W. E., Studies of Inheritance in Rabbits, Carnegie Inst. Publ., 1909, 
p. 45. 
® Patterson, J. T., Science, n.s., vol. LII, no. 1341, p, 250, 1920. 
