F. Pitt 109 



usually dominant to its absence, as will presently be shown when the 

 evidence concerning the hybrids between the ferret and polecat is given. 

 It is probable that in fawn and in " fitchet " ferrets we meet with dilu- 

 tion factors that complicate matters, but the numbers so far bred are too 

 small for the facts to be elucidated. The various matings of which I have 

 records in which fawn-coloured ferrets have been involved are tabulated 

 below. It will be seen that in a cross of red x dark the white class was 

 larger and the red smaller than expected. 



Tabulated results obtained from matings of erythristic ferrets : 



IV. Ferret-Polecat Hybrids. 



(a) As the characters in which the polecat and the ferret differ have 

 already been described, it is unnecessary to go over them again ; I will 

 only remind the reader that they consist of certain cranial peculiarities 

 and of coat colour. There is also considerable difference in temperament, 

 the domestic animal being placid and easy-going, the wild one very much 

 the reverse. 



(b) In 1912 I was fortunate in obtaining a very fine male polecat 

 from Cardiganshire, also a female, but as she never bred she is only 

 mentioned here because she served as a standard with which to compare 

 the female hybrids that were subsequently reared. The male, No. 5 in the 

 accompanying pedigree (p. Ill), was mated with an albino ferret of known 

 pure white ancestry for several generations. The resulting litter num- 

 bered five, two males and three females, all dark in colour, and showing 

 complete dominance of the wild type in the F^ generation. Perhaps the 

 words "complete dominance" need qualification, for, notwithstanding the 

 hybrids were much darker than any so-called polecat ferret, they did 

 show slight traces of the ferret side of their ancestry, inasmuch they had 

 whitish under-fur instead of the buffy-grey wool of the true polecat. 

 Nevertheless they were very dark in colour, the black-brown of the long 

 hairs having the slight purplish sheen so characteristic of the polecat. 

 The polecat temperament too was fully apparent, for, despite the fact 

 they were made great pets of, and were constantly handled, they were 



