PREFACE V 



use of restraining dyes to produce effects of coloration 

 beyond the power of lens and color-sensitive plates. The 

 results exceed in value the familiar pen drawings of 

 reptiles ordinarily employed in popular works. Among 

 the latter a snake is merely a scaled creature, and, unless 

 exhibiting some striking development, produces no last- 

 ing impression in the mind of the student. It may tally 

 with every word of an attending description, but would 

 probably not be identified with an actual specimen seen 

 soon after. Expert photography imparts, in a work 

 like this, a strong individuality to each species, positively 

 branding the various forms and capable of imitation only 

 by such exceedingly painstaking draftsmen as are em- 

 ployed to illustrate the highly expensive monographs of 

 the great museums — institutions having the means to pay 

 for the labor of drawing a reptile scale by scale, each 

 minute part of the integument receiving its share of 

 work according to color value or shading and intricate 

 structure. The cost of such labor would be enormous 

 in a work like this, placing it beyond the reach of most 

 popular readers. It is such illustrative work the author 

 has tried, as far as possible, to approach in value in the 

 pages following. The several hundred illustrations are 

 the result of his personal endeavors. A number of the 

 specimens photographed have been exhibited in the Rep- 

 tile House of the New York Zoological Park. 



For the encouragement and suggestions of Director 

 William T. Hornaday, of the New York Zoological 

 Park, the author wishes to express his hearty apprecia- 

 tion and esteem. In the pages that follow the author 

 has drawn freely from observations made in the splendid 

 Reptile House erected by the New York Zoological 

 Society, Avhom he has the honor of serving. 



Throughout this work the classification of Dr. George 



