237 CHAPTER XIX. COUNTY AND DISTRICT DISTRIBUTION. METHOD OF INVESTIGATION-SOURCES OF INFORMATION- 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 naturalists 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 large number of correspondents I have had in the last few years, all of whom were evidently interested in the subject. I have endeavoured to get a record of our serpents for every county in the kingdom, and for this purpose approached the secretaries of Field Naturalists' Clubs in all those counties where such societies are working. In each case my inquiries took the same form, and the queries are reproduced here in the hope that future correspondents will supply me with local records on these lines. The questions asked were:— 1. Which snake is most common in the county (or district) of? 2. What is the average length of the adder here? 3. What is the average length of the ring snake here? 4. Does the smooth snake occur to your knowledge? 5. Does the small red viper occur? 6. Kindly add any other note on snakes you deem of interest. The quotation of the questions will explain the uniform nature of the arrangement of the county reports. In addition to field naturalists I have had the assistance of some of the curators of our museums, and of authors of books on county fauna, and have so been able to bring together a mass of facts which, though some of it was in existence before, was so scattered that it was not available for purposes of comparison. |