50 THE ZOOLOGIST. 



favour in the eyes of a widowed hen of the other, or may even 

 fight for the hen with her legitimate spouse (I have seen a record 

 of such a case in the columns of * The Field '), it certainly seems 

 by no means unlikely that a hybrid should now and again be 

 produced. 



Against this it may be urged that such crosses are repugnant 

 to the instincts of the birds, and that although their instincts 

 may occasionally be overcome in the case of polygamous birds, 

 where often the young cocks are prevented from mating by older 

 and stronger birds, they would operate with much more certainty 

 amongst monogamous birds, and even to the extent of absolutely 

 preventing such unions. 



That this or some other cause does operate most power- 

 fully, is, I think, sufficiently shown by the following suggestive 

 comparisons : — 



(1) Hybrids between Capercaillie and Blackcock, both being 

 polygamous, not at all uncommon. 



(2) Hybrids between Blackcock and Willow or Red Grouse 

 one being polygamous and the other monogamous, decidedly 

 uncommon. 



(3) Hybrids between the various species of Ptarmigan, 

 (Lagopus), all being monogamous, either unknown or excessively 

 rare. 



On the whole, however, the a priori arguments are decidedly 

 in favour of the possibility, and even probability, of such a cross ; 

 and this conclusion lends additional weight to the claims of 

 Prof. Newton's specimen to be what it certainly looks like — 

 a genuine hybrid between the Red Grouse and Ptarmigan, or 

 the Ptarmigan and Red Grouse. 



To sum up ; my consideration of the question at issue leads 

 me to the following conclusions : — 



(1) There is not in the Natural History Museum at South 

 Kensington any example of such a hybrid, nor is there any record 

 of one ; nor, for that matter, of any hybrid at all between different 

 species of Ptarmigan, in the works of any British ornithologist 

 with which I am acquainted. 



(2) The greater number of the alleged cases communicated 

 to ' The Field,' or other periodicals, break down in the descrip- 

 tions, and none that have come under my observation could be 

 accepted by ornithologists without further verification. 



