(xc) 



111 tlic li(nly of the Hevisioii many details of the morphology of the 

 Sphimiidiii' will lie mcntioiUMl whicli we liave only touched upon in the fore- 

 goiii,;: snmmary. Thoii.irli the Hawk Moths are a compact group, the diversity 

 of dcvcloiinient within the family is iieverthelcss so great that the subject is not 

 in any way exhausted by our researches, to whieh time, material, and ability 

 have set limits. Classilication wa-t the avowed object towards whicli the 

 researches in the structure of the Sphiiigiihie were undertaken. However, 

 since classification as we conceive it gives expression to the blood-relationship 

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

 shiji can be given without an inqniry into the phylogenetic development of 

 the (characters which distinguish each Hawk Moth, it is manifest that with the 

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

 entered uiion which bear njion the broad questions of development of the 

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

 through the embarrassing mass of detail iireseiited by the 770 species of Hawk 

 Moths. The value of detail for the solution of general (|uestions has again 

 and again been foicud ujion us during the pre[)aration of this Revision. 



At first sight it apjiears to be of little consequence whether 75tJ or 770 

 species of Spldiiqidae are known ; whether Aleuron iphis is the same as 

 neglectum, or distinct ; wliether Odontosida belongs to the Philampelinae or 

 Ambulicimie. The distinguishing 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 putting them into some kind of order, there 

 would be justification for those who smile at the efforts of mere S3-stematists. 

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

 different aspect, if the solution of the i|U('stion "species or no species" is 

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

 How? anil Wliy'r' in Nature. Tiiat Uijloicus perelegans has a grey form so 

 closely resembling lli/loicus e/iersix that it has hitherto always been mixed up 

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

 Bnt if we add that this grey form has a reduced paronychiuni like r/ic/v/s, while 

 the paronychiiiiii is always distinctly lobeil in the black-backed form, a difference 

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

 what is elsewhere a specific or generic character breaks down at once, and it is 

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

 elegans with c/tersis being observable only under a high magnifying power, there 

 are similarities which are decidedly not mimetic. Whether the right or left harpe 

 of I'ac/ii/lia durrcta is the stronger developed, or whether both are the same, 

 is as indifferent a qnestion to the non-specialist as is the result of a cricket 

 match to a Contineiital. However, if one knows that in the Sfmi/iar with 

 asymmetrical development of the clas])ers the left side is the more reduced, 

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



