FlG. 119. Diagram to illustrate the effect ol the animals' 

 markings shown in Fig. 120. These lour figures show a 

 graduated development from No. 1, which represents nothing 

 substantial, to No. 4, which represents an edge of substance 

 showing against a shadowed cavity beneath. Animals' 

 markings, almost invariably, are on the general principle ol 

 No. 4. 



Fig. 120. Bits ol animals' patterns, all representing lmt«s r 

 i. e., shadowed cavities over which sharply defined edges 

 "relieve" (like wood, leaves, rocks, etcj. Among these are 

 mingled reproductions of actual holes to show how close 

 is the resemblance. (See Fig. 119.) 



