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veiy limited number of genera and even of species in these 

 genera, and much less often than is generally supposed. It might 

 throw some light upon the subject if some of your correspondents 

 would inform your readers of any instances which may have come 

 under their observation, and at the same time say where the 

 specimens can be seen. With the exception of those between 

 the Pheasant and Black Grouse, and the latter bird and the 

 Capercailie (the former cross cannot be considered a cross between 

 birds in a state of nature) (but even in these cases no further 

 cross appears to occur,) I have only seen instances amongst the 

 Ducks, and it seems probable if all those known were added 

 together, one would not occur annually amongst the thou- 

 sands of wildfowl which are taken. In the wild state crosses 

 between extraordinary or occasional varieties, as albinos, of 

 the same species really seldom occur, the instances of such varie- 

 ties are so very limited in number ; and, as a general rule, the 

 variations amongst species are so trifling, that it is difficult to 

 describe how they vary, each individual probably being a shade 

 lighter or darker, larger or smaller, or more or less spotted or 

 marked. True it is, we find sometimes a wild white or pied bird, 

 but it would appear that nature does not like these, as they do not 

 apparently increase in number ; and probably if pains were not 

 taken to keep the particular varieties of species amongst birds 

 produced by domestication separate, we would find that the varie- 

 ties would gradually become assimilated, and probably we should 

 in the course of time get a variety from the whole which would 

 be best adapted for the climate and circumstances, and probably it 

 would much resemble the original form of the species from which 

 the several varieties descended. Many of our native species 

 refuse to breed in confinement : some do breed, but recent domes- 

 tication does not seem to alter their general appearance, and 

 probably, in spite of all experiments made with them, except 

 crossing them with other varieties, they will continue as they are. 

 In a notice which I observed latch in Tin- Fidd, I saw it stated 

 that Dr. Fleming considered the Wild Duck (Anas bovchas} as we 

 have it, the parent stock of all Ducks. Is it to be iniVm-d that 



