Natural History 371 



no literature on the subject. All facts had to be gathered 

 directly from Nature. My first attempts at recording 

 tracks were made with pencil and paper. Next, realizing 

 how completely the pencil sketch is limited by one's own 

 knowledge, I tried photography; but it invariably happens 

 that not one track in ten thousand is fit for photographing, 

 and it cannot be taken except when the sun is about thirty 

 degrees above the horizon — that is, high enough to make 

 a picture, and low enough to cast a shadow of every detail. 

 Thus photography was possible only for about an hour in 

 the early morning and an hour in the late afternoon. But 

 the opportunity in the meanwhile usually was gone. I then 

 tried making a plaster cast of the tracks in the mud. Only 

 one such in a million was castable. As a matter of fact, 

 none of the finest were in the mud; and the much more 

 interesting dust- tracks were never within reach of this 

 method. For most practical purposes I have been forced 

 to make my records by drawing the tracks. 



NO TWO TRACKS ALIKE 



The trailer's first task is to learn the trails he means 

 to follow. The Red Indian and the Bushman, of course, 

 simply memorize them from their earliest days, but we 

 find it helpful and much easier to record them in some way. 

 Apart from other considerations, a form is always better 

 comprehended if we reproduce it on paper. As a general 

 principle, no two kinds of animals leave the same track. 

 As a matter of fact, no two individuals leave the same 

 trail. Just as surely as there are differences in size and 

 disposition, so there will be corresponding differences in 

 its trail; but this is refining beyond the purposes of prac- 

 ticability in most cases, and for the present we may be 

 satisfied to consider it a general rule that each species 



