382 THE STRUCTURE AND LIFE OF BIRDS chap. 



same as in Mr. Mivart's Elements of Ornithology : in 

 the one the owls form a separate order, in the other 

 they are a sub-order of the Raptores. Botanists are in 

 a very different position : the battles of their rival 

 classifiers are fought over far more minute points. 

 Ought a certain form of briar, willow, or rose to be 

 counted as a species or a variety? The question 

 whether a particular genus shall be included among the 

 rushes or the lilies is one that exceeds the ordinary 

 magnitude of the problems that beset the classification 

 of British flowers. 



Reptiles also, from a classifier's point of view, present 

 a striking contrast to birds. They are divided into 

 great and unmistakable orders. There are the Tortoises, 

 the Lizards, the Crocodiles, the Snakes. With birds, 

 though the number of species is very great, the differ- 

 ences are very small ; it is only by a minute study of 

 many, often obscure, anatomical points that a sound 

 system of classification has been arrived at. Unfor- 

 tunately a system founded on such a basis, however 

 true it maybe, must always have this drawback — that 

 an amateur must accept a great deal of it on trust. 

 I shall try to make clear a few of the chief points on 

 which the best and more recent systems depend. And 

 these few will be selected not only for their importance 

 but because they may be understood without much 

 technical knowledge. If they seem insufficient, it 

 must be remembered that there is a great array of 

 equally telling, but less easily appreciable, facets in 

 reserve. 



There are, as I have said, eleven thousand known 

 birds. The first step is easy : they can be divided 



