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CHAPTEE XIX. 

 COUNTY AND DISTRICT DISTRIBUTION. 



METHOD OF INVESTIGATION — SOURCES OF INFORMATION — 

 COMPARISON OP RESULTS OBTAINED. 



The study of the variations of the species in any 

 given order of animals is one of the most fascinating 

 in Natural History, and what follows in this book is 

 an attempt to indicate the most important differences 

 of distribution and relative frequency of our three 

 British serpents ; and as it is, as far as I am aware, 

 the first attempt of its kind in this branch of our 

 fauna, it must necessarily be imperfect. A perusal 

 of the various county records will show that it would 

 be the work of a lifetime for any one investigator to 

 thoroughly work up the Ophidia of every county, 

 even in a small country such as ours. The only 

 practicable method is to enlist the aid of field natural- 

 ists all over the land, and compare and tabulate the 

 results so obtained. This has been the method I 

 have adopted, being encouraged to do so by the very 



