(xc) 



III tlic liiiily of the Hcvisiou many details of tlie niorpliology of the 

 Sftliiiiqiddi' will be mentioned wiiich we iiave only touched upon in the fore- 

 goin.ij Kunimary. Thoiisi'li the Hawk Moths are a compact group, the diversity 

 of de\elo))meut within the family is nevertheless so great that the subject is not 

 ill any way cxliansted by our researches, to which time, material, and ability 

 have set limits. ( -lassification was the avowed object towards which the 

 researches in tlie structure of the Sphhiyidae were undertaken. However, 

 since classification as we conceive it gives e.Kpressiou to the blood-relationship 

 of the forms classified, and since no sound verdict about the degree of relation- 

 ship can be given without an inquiry into the phylogenetic development of 

 tlie ciiaracters which distinguish each Hawk Moth, it is manifest that with tiie 

 apparently narrow object of giving a classification of the Sphingidae issues are 

 entered uihiii wiiich bear njion tlie broad questions of development of the 

 animated world, of which questions we have never lost sight in struggling 

 througli the embarrassing mass of detail i)resented by the 770 species of Hawk 

 Moths. The value of detail for the solution of general questions has again 

 and again been forced upon us during the jireparation of this Revision. 



At first sight it ajipears to be of little consequence whether 751) or 770 

 species of Splniiyiilde are known ; whether Aleuron ipliis is the same as 

 neglcctum, or distinct ; whether Odontosida belongs to the Philampeliiiae or 

 Ambuliciiiae. The distinguisliing characters upon the discovery of which so 

 much labour is expended in classificatory research may not seem to be worth 

 the trouble, being apparently of interest only to the collector and specialist. 

 Indeed, if systematic work did not go beyond distinguishing and naming the 

 forms of animated nature and jintting them into some kind of order, there 

 would be justification for those who smile at the efforts of mere systematists. 

 However, the discovery of distinguishing characters assumes at once an entirely 

 different aspect, if the solution of the question "species or no species" is 

 considered but a stejipiiig-stone towards the higher aim of understanding the 

 How? and Why? in Nature. That Ili/loicus pere/egans has a grey form so 

 closely resemliling Ili/loicits chersis that it has hitherto always been mixed up 

 with it, will not interest anybody except perhaps North American Lepidopterists. 

 But if we add that this grey form has a reduced paronychium like clwrsis, while 

 the paronychium is always distinctly lobed in the black-backed form, a difference 

 often distinguishing genera or even subfamilies in Lepidoptera, the rigidity of 

 what is elsewiiere a s[)ecitic or generic character breaks down at once, and it is 

 further evident that, tlie agreement in the paronychium of the grey-backed per- 

 elegans with chersis being observable only under a high magnifying power, tliere 

 are similarities which are decidedly not mimetic. Whetlier tiie right or left harpe 

 of Fachi/lia darcetu is the stronger developed, or whether both are the same, 

 is as indifterent a question to the non-specialist as is the result of a cricket 

 match to a Continental. However, if one knows that iu the Sesiinae with 

 asymmetrical development of the claspers the left side is the more reduced, 

 and remembers the haste with which " laws " in development are often 



