Taking into consideration the great difference in the lives and habits of the orders in question, I do not think the interbreeding of species of the genus Tetreao is any strong proof of the correctness of Dr. Hagen's conjecture. Robert Mudie, in his “Feathured Tribes of the British Islands,” speaking of Tetreao tetrix, says: “During the latter part of autumn and winter the males live together in flocks and in a state of the most perfect harmony