INTRODUCTION. 



OL'li reseiiivlies in SijhiiKjid'ic, wliicli have buuii curricil on conjointly for 

 scvenil years, and of wliidi we now imblisli llie results, were underlalien 

 widi the imrpose of giving a sound basis to the classiticatiou of these insects 

 by an extensive stiuly of tiieir morphology. 



(Jlassitieation is an iiiteriiretation of facts. The facts are to a great e.\tent 

 delails of the anatomy and morphology i>f the beings classified. As it is, 

 therefore, largely circumstantial evidence which guides the classiiiei', the first 

 step towards a correct classification is tti find out as many facts as possible. 

 In interpreting these fads nr characters jiresented by I he individuals— the indi- 

 vidual is the basis of all n^search — one starts with the assum[)tion that what 

 has been foimd to be li'ue in the necessarily limited number of specimens 

 investigated, holds good also in the vast multitude of individuals uot compared. 

 The possibility of an error in this respect can be lessened by the comparison 

 of a large material of individuals. How large it should be, nobody can predict. 

 To ascertain the extent of variatiou of the chief classiticatory unit, tlie species, 

 the material is never too extensive. 



On the knowledge of the extent nf variation of the species of a family 

 depends the stability of the superstructure of genera, tribes, and subfamilies. 

 An ideal classificatiou could be drawn up, if all the species were known which 

 are in existence and which have been. As this premiss cannot be fulfilled, we 

 have to be content with the species that are known. And here, again, the 

 foundation of the superstructure will be the safer the more species have been 

 examined. 



We have endeavoured to comply with these three primary demands on a 

 classifier as far as it was possible for us : many facts, many individuals, many 

 species. We have not restricted ourselves to a comparison of the [lattern, 

 general appeai'iuice of the body and wings, and of the neuration, but have taken 

 into the scope of our research every [lart of the skeleton of the imagines, and 

 hence have given a broader basis to our conclusions than has ever before been 

 done in this family. Since the structure of the Hawk Moths has never been 

 studiid III any extent — the s^,ltinijiil<tc being in ihis respect one of I lie most 



