1 7 2 Summer Studies of Birds and Books CHAP. 



of a man who, like Aristotle, wished to deal with all 

 kinds of animals, yet had no means of distinguishing 

 them, except the common names which country folk 

 had given them. Of course there were many rare or 

 out-of-the-way species which had no names at all; 

 and thus we find Aristotle often obliged to describe 

 them as best he could without a name at all. Then 

 remember that one name is not enough to enable us 

 to be sure of the particular kind meant. It is only 

 since the universal application by Linnaeus of the 

 principle of the double Latin name that we have 

 been enabled to know with tolerable certainty what 

 species is referred to by a writer ; and even now the 

 difficulty is often so great that it has lately been pro- 

 posed to adopt, in certain cases, a system of three 

 names. Let us consider this point for a moment, in 

 order to understand the chief difficulty that Aristotle 

 had to contend with, and to appreciate the curious 

 fact that for two thousand years after his time natural 

 history remained a hopeless chaos. 1 



Supposing you wished to find a book in a large 

 library to which there was no catalogue. If the 

 books were arranged in some order the poets to- 

 gether, the historians together, and so on you would 



1 To illustrate this confusion I may quote the heading of 

 Willughby's account of the Bar-tailed Godwit (ed. 1678, p. 292) : 

 ' The Godwit, called in some places the Yarwhelp or Yarwip, in 

 others, the Stone Plover. The Barge, or jEgocephalus of Bellonius 

 as I take it. An Fedoa Gesneri ? An Rusticola Aldrovandi ? " 



