APPENDIX VI 



NOTES ON CLASSIFICATION BY ORDERS 



The Order to which each bird belongs is indicated in the last column 

 of the Tables. This classification is based chiefly on resemblances 

 in physiological or anatomical structure, which are invisible to the 

 ordinary observer in the field. In most cases also it is impossible to 

 describe the resemblances in simple language. The classification, 

 however, is of the utmost scientific importance as affording a clue to 

 the evolutionary history of bird life. A cursory acquaintance with the 

 grouping of the birds will, moreover, often add fresh interest to their 

 observation, and may serve as an introduction to more advanced 

 study. 



Such an acquaintance can easily be acquired by means of the following 

 list of Orders with the birds belonging to each. The accompanying 

 descriptive notes give some of the outward characteristics of the birds 

 in each order. It will be noticed that some of these characteristics 

 are common to various Orders. The actual classification is usually 

 determined by combinations of some or all of these features together 

 with some internal characteristics. 



These brief notes on the outward features alone may, however, be 

 interesting, and may also sometimes be useful as an aid to identification . 



The generalisations are intended to'apply only to the birds described 

 in this book. They are not always applicable to the rarer birds, or to 

 foreign birds belonging to the Order in question. 



COLYMBIFORMES (" DIVER-SHAPED ") 



Water-birds with webbed or lobed toes ; hind toe very small ; legs 

 set very far back and much flattened. Sexes alike. Young active and 

 soon able to feed themselves. Food chiefly fish. 



Diver, Black-Throated Grebe, Great-Crested 

 ,, Great Northern ,, Little or Dabohick 



Red-Throated Red-Necked 



Grebe, Eared Slavonian 



The Divers have strong, straight bills ; short, narrow, and pointed 

 wings ; . short tails and webbed front toes. 



The Grebes have long necks ; no tails ; front toes surrounded by 

 lobes of skin, and frequently crests or ruffs in the breeding season. 



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