104 Polecat, Ferret, and Polecat- Ferret Hybrids 



(6) Description of the Feri'et. It has been long assumed that M. furo 

 is a domesticated form of the polecat, which it so much resembles in 

 general build and character, the fact that the majority of ferrets are pink- 

 eyed cream -coated albinos being considered confirmatory rather than 

 contradictory of the idea, especially as pigmented individuals resemble 

 polecats in their colouring and facial markings. That is to say they 

 resemble them in their general type of marking, but not exactly, as all 

 "fitchet^" ferrets I have seen have been much lighter in hue than the 

 palest of polecats, showing, too, broader facial markings, so that there is. 

 a marked reduction of pigment compared with the wild animal. Not 

 only are the white facial markings so much increased, but the woolly 

 underfur, which in the polecat is invariably a buffy-drab colour, is whitish 

 in the dark ferret. The "fitchet" ferret bears in outward appearance the 

 same relation to the polecat that a half-printed photograph bears to the 

 fully printed one from the same negative. The head of the ferret is 

 narrower than that of the polecat, appearing when seen from above as an 

 isosceles triangle, whereas the face of the polecat makes an equilateral 

 triangle ^ As regards size the average ferret is a trifle smaller than the 

 average polecat, it being a large male which exceeds 380 mm. head and 

 body measurement. The appended table shows the respective measure- 

 ments. In cranial characters we come to some important differences be- 

 tween the two forms, which differences have made Miller(3) express the 

 opinion that, " the ierret, Martes furo Linnaeus, though usually assumed 

 to be a domesticated variety of Mustela putorius, appears to be more 

 nearly related to the Asiatic M. eversmanni Lesson." The differing points 

 in the ferret's skull are : the more narrow constricted post-orbital region, 

 averaging in the male only 13 mm. in breadth, against the 18 mm. of the 

 male polecat, which gives the skull a "small-waisted" appearance ; the more 

 inflated and less triangular auditory bullae ; and the smaller carnassial 

 teeth. The only skull of M. eversmanni that I have been able to examine 

 showed a marked likeness to the ferret's in all the above characters, but 

 every ferret's skull I have seen has differed in one respect from both the 

 single specimen of M. eversmanni, and from every polecat's that I have met 

 with, this character being the shortness of the ridges that proceed from 

 the post-orbital processes towards the brain-case, and which converge at 

 a much blunter angle than they do in the polecat. The length in seven 



1 " Fitchet" is a term commonly employed by keepers, rabbit-catchers, etc., to denote 

 the dark or so-called " polecat " ferrets. I have avoided herein the use of the latter word 

 for fear of misunderstanding. 



2 Mr A. H. Cocks first drew attention to this in the Zoologist, Vol. xv. 1891, p. 344. 



