198 A MONOGRAPH OF THE PHEASANTS 



more specialized. White is always an extreme achievement in pigment radiation, or 

 rather elimination, and their coloured young show how recently the adult hue has been 

 acquired. But, on the other hand, the greater number of four-and-twenty tail feathers in 

 the blue-grey auritum is in its way as extreme a specialization — excelled in the family 

 Phasianidae only by the adult Lobiopkasis. Thus the complexity of evolution is for ever 

 being impressed upon us — specialization correlated with generalization and vice versa in 

 closely related organisms. Only by the sum total — the balance after the intricate addition 

 and subtraction of all its character units, and even then only by vizualizing the genealogy 

 in three planes of space — can we ever hope successfully to orient any species in relation 

 to its predecessors and contemporaries. 



END OF VOL. I 



