232 Preface. 



older local naturalists seem to think. True, a few large and con- 

 spicuous species have disappeared entirely ; some birds and insects 

 have been driven further from the London area, many have become 

 comparatively rare, but one feels satisfied that the pathos in " now 

 extinct," and similar notes, repeated frequently in some of our 

 friends' lists, is due, often, to one of two causes, viz., either (1) their 

 active collecting was done some years ago, and their more hap- 

 hazard outings now naturally do not produce such good results as the 

 more strenuous collecting of their younger days, in addition to which 

 they themselves no longer make a point of noticing species not abso- 

 lutely rare ; or (2) they found their conclusions on a limited 

 experience, and fancy that, because " Ichabod " is written on their 

 old and favourite haunts, fairly easy may-be of access, similar 

 ground farther out is equally unproductive, when, really, sufficient 

 search has not been made to discover new haunts. 



It is trusted, therefore, that the present lists will prove useful in 

 two ways : (1) To form a basis to which additions, both in the 

 matter of species and localities, may be made, and thus a more 

 thorough knowledge of the local distribution of species be obtained. 

 (2) To awaken fresh energy in the direction of enquiring into the 

 changes now taking place in our fauna, what species are influenced 

 beneficially, and what prejudicially, by the nearness of man ; in 

 short, to form a safe groundwork for the conclusions of future 

 naturalists as to the real causes of the change of fauna, which the 

 district under consideration is undergoing. 



