Introduction xxv 



tool, a trusty servant and recorder, which the artist can use to 

 as good advantage as any one else. Scientific books dealing 

 with the anatomy and development of animals will always re- 

 quire good drawings for the illustration of their subjects, and 

 these are preferable to poor photographs ; but for the study of 

 animal behavior in both the invertebrates and vertebrates the 

 camera is at times immeasurably superior to brush or pencil. 

 Popular natural -history books have already a large body of in- 

 valuable material to draw upon for illustrative purposes, and 

 the often crude, impossible, or imperfect drawings, which "have 

 long done service in the past, will gradually give place to truthful 

 delineations of animals at home, and in the midst of that nature 

 of which they form a part. 



