( ci ) 



We have adopted tliis kind of connectiou for the sake of simpHcit}- of printing 

 Tlie pedigree should read as follows : — 



Hh'iiloxoi/ia Cizara Rethevd Eiiiiininuia 



If couiieeteLl like this, each genus may have aeipiired its own specialisations after 

 the point of separation, and each may also liave preserved generalisations lost 

 by the nearest allies after separation. 



GEOGBAFHICAL DISTBIBUTIOIT. 



The Hawk Motlis are an essentially trojiical family, the number of 

 species existing in the temperate regions being comj)aratively small. Very 

 few Sjjhingidae. extend into the Arctic Regions, and then only as occasional 

 visitors, no species being known to breed beyond the Arctic Circle, though some 

 {Amorpha pojinli and amnrcnais, SjJiht.t oeellat i, Celcrio ii<UUi, Ili/loicus 

 pinastri) may be expected to occur as far nortli as their food-plants go. As 

 the greater number of species have a powerful flight, and are, moreover, often 

 wanderers, covering wide distances, the area inhabited by some of tiie s])ecies 

 is very extensive. 



The proi)ortion of geographically uniform species of Sjtl/inyiddi^ is large as 

 compared with other families of Lepidoptera. Methodical researcli has jn-oved 

 to the systematist tiuit countries like West and East Africa, India and the 

 Malayan Islands, Central and South America and tiie Antilles, tiie Andes and 

 Eastern Brazil, etc., etc., are inhabited by sj)ecial races of nearly every species 

 of Hutterfly there occurring. The stiuleiit is, a priori, certain in most cases 

 that a species of Butterfly not yet discoveretl in some such district will, if 

 occurring, exhibit some kind of <listiuction. In mpluryidne a priori conclusions 

 like this would mostly be wrong. Since geographical variation depends on 

 geographical isolation, it is evident that those Lepidoptera which are stationary 

 are far more variable geographically than those which are not prevented by 

 geographical barriers from constantly crossing over to other districts. The 

 l)Ower of flight, however, is as such no i'actor elfacing the geogra{)hicaI 

 barriers. The swift-flying Ckaraxcs and I'apilio vary geographically as much 

 as do slow-flying Butterflies ; and in birds — which may be called stationary 

 from the point of view of a student of geograpliical distribution in so far as 

 they breed in their native country — geographical variation is also tiie rule and 

 not the exception. On the contrary, the more powerful the flight, the more is 

 an animal enabled to flee from or resist the factors of passive distribution 

 (water and windj, to counteract their influence. But if powerful flight and the 

 haliit of wandering during the period of propagation coincide in a species, the 



