INTRODUCTION 



THROUGHOUT this work the writer has tried to assist the 

 beginner yet he feels that he has left out little that will interest 

 the technical worker. He believes that the trend of scientific 

 publications should be more in this direction. Let us consider 

 but one argument, and that in relation to the study of reptiles. 

 Suppose an intelligent farmer, with an inclination for the study 

 of popular natural history, should find a snake upon his lands, 

 and, wishing to find whether it was harmless or poisonous, opens 

 a strictly scientific book, dealing with North American reptiles. 

 What does he find? Elaborate descriptions of anatomical 

 characters, many of these internal, and these descriptions under 

 technical headings, each followed by a long list of synonyms 

 and often a lengthy debate as to the former classification by 

 other scientists than the author; about the only popular words 

 in the description, are the articles "the" and "a"; even the 

 colours are defined in intricate fashion. To this man, such 

 a book is useless. He has no time to master the bewildering, 

 new language he has discovered, so is unable to learn whether 

 the snakes living on his farm are harmless or dangerous, bene- 

 ficial or otherwise. 



In preparing. the descriptions, the writer has excluded com- 

 plicated references to structure. Of these characters, his valu- 

 able assistant, the camera, has described intricate details far 

 better than if such were put in type; in fact, many of the species 

 need little description beyond that of their colours and si^e, 

 as the photograph of the animal and the attendant illustrations 

 of the head (above and from the side) show most of the features 

 of the structure and pattern. 



Use of scientific names. The practice of often changing 

 generic names, simply according to the ideas of this or that 

 authority, is very confusing to any but the advanced student 

 and adds to the steadily increasing list of synonyms. The writer 

 has made no attempt to discuss the alleged good-standing of 



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