Vlll AUTHORS PREFACE, 



intended to appear in vol. v., but which now forms the con- 

 cluding section of vol. iv., embraces a short sketch, limited 

 to systematic and faunistic works, of the bibliography of 

 Lepidoptera. In consequence of the amount of extra matter, 

 it has been decided to give a fuller subject-index than in the 

 earlier volumes of the series. 



It is not pretended that the essays on Classification or 

 Bibliography are exhaustive ; and some books have been 

 excluded from the latter solely to avoid repetition, because 

 they are noticed in other parts of the work. It is hoped, 

 however, that these chapters will be useful to students who 

 wish to take up the study of Lepidoptera from a more serious 

 point of view than that of mere collectors or amateurs. 



Finally, attention has recently been called to the reckless 

 manner in which some collectors virtually exterminate local 

 insects : and the Entomological Society of London has 

 appointed a committee to consider the subject. It is the duty 

 of every right-feeling Entomologist (even if only an amateur, 

 and whether collecting at home or abroad) not to kill a 

 single specimen more than he actually requires for scientific 

 purposes. Nor is there any reason to object to an Entomo- 

 lof^ist being only an amateur, or, as it is sometimes termed, 

 " a mere collector," for the range of Entomology is vast, and 

 there is plenty of room for workers in all directions. A 

 Lepidopterist may not admire a fly or a beetle, but he need 

 not look down on those who do ; and a systematist need not 

 underrate the work of a physiologist, or vice versa. Specialism 

 there must be in all branches of science, but there need not 



