Volume XI SEPTEMBER, 1921 No. 2 



LIBRARY 



NEW Y04<lt 



•OTANICAL 



aAKUe^ 



NOTES ON THE GENETIC BEHAVIOUR OF CERTAIN 

 CHARACTERS IN THE POLECAT, FERRET, AND 

 IN POLECAT-FERRET HYBRIDS. 



By FRANCES PITT. 



(With One Text-figure and Plates XV and XVI.) 

 CONTENTS. 



PAOB 



I. Introduction 99 



II. Description of the Polecat and the Ferret 101 



(a) The Polecat 101 



(b) The Ferret 104 



III. Variation in the Polecat and in the Ferret 105 



(a) The Polecat 105 



(6) The Ferret 107 



IV. Hybrids between the Polecat and the Ferret .... 109 



(a) Material used in Experiments 109 



(b) The Hybrids 109 



(c) Notes on the Development of the Young Hybrids . . 110 



(d) Second Litter 112 



(e) Reciprocal Cross 112 



(/) Fa Generation 112 



(g) Fi X the Feri-et 112 



{h) Fi X the Polecat 113 



(i) Weakening of Pigmentation in Hybrid x Ferret Crosses . 113 



V. Recapitulation and Conclusion 114 



I. Introduction. 



These notes deal with the genetic behaviour of colour and certain 

 cranial characters in the ferret, Martes furo (Linnaeus), in the polecat 

 Mustela putorius (Linnaeus), and in the hybrids obtained by crossing the 

 two species. Unfortunately, owing to the difficulty of keeping a number 

 of flesh-eating animals, which difficulty was much greater during the 

 War, and since then to the loss of all my ferrets from distemper, my 

 observations and results are very incomplete. They are only published 



Journ. of Gen. xi ^ 



