596 FURTHER NOTES ON 
in this district are of the true Tetrao medius type, while those 
shot during the present year exhibit the transition-forms, 
affords matter for much consideration. 
According to the keepers, a hen Capercaillie appeared on 
this ground some years ago, went about with the Blackcock, 
and this was the origin of the first true Hybrid Cocks. 
But how is it that the specimens last killed come nearer to 
the Capercaillie? This species certainly never pairs with the 
Greyhen, and it is also hardly credible that a cock Capercaillie 
would, during the drumming-season, leave its woods, which 
were well stocked with hens, to fly for many miles over the 
open country and settle in thin fir-woods absolutely unsuited 
to it. 
Is Tetrao medius, after all, a fertile or barren hybrid? I 
believe it to be fertile. Now, if its reproductive capabilities 
be granted it is possible that a Capercaillie hen might be 
fertilized by a hybrid bird, or even a hybrid by a hybrid; and 
there is no saying whether such a union might not produce a 
very singular form of reversion to the grandparents, in this 
case to the Urogallus type. 
One thing is proved—Tetrao medius is not a true species, 
but a cross, for such enormous differences can only occur 
amongi hybrids. Hybrid hens also exist, and if the males 
have reproductive powers the same must hold good of the 
females. 
At a distance of twenty paces at the most I saw two hens 
on the ground near a Hybrid Cock, and their reddish colour 
and peculiar size at once showed me that they were neither 
Capercaillie nor Blackgame; for I have had so much experience 
in the pursuit of these birds in the most varied localities, and 
have seen so very many of them, that I can quite rely on 
the accuracy of my observation. The call of these hens was 
also so different from that of both their ancestral species that 
I was at once struck by its strangeness. 
