TIIK (OI.OXIZATION OK NKW i;\(il.ANI) 1065 



If, now, we weiv toiliaw a picture ot'tlie series of events wiiieh followed 

 the great glacial epoch, we should see the ice receding by slow but con- 

 tinued steps, followed closely by the plants which can i)car the cold, 

 and those by the creatures which food upon them, until at hist the 

 region becomes completely re-populated. As the cold diminished 

 and the seasons inipro\ed, we should gradually reacii the condition of 

 things that we find at the present day, viz., in the northern and higiier, 

 cooler parts, relics of those forms which can endure the cold ; in the lieart 

 of the region a great body of forms, which, considering tiie long continu- 

 ance of its present condition, may be deemed in a limited sense endemic ; 

 and the existence along the southern border of more southern forms, 

 striving to gain and maintain a foothold. 



If we analyze the generic types which exist at the present day in New 

 England, we shall find that the other representatives or the nearest allies of 

 al)out one-half of them belong to the region lying to the south ; the bulk 

 of the remainder would be those whose other members occur in other 

 parts of tiie north temperate zone, whether in America or in the Old 

 World : a few would be found restricted otherwise to the region lying to 

 the north, and a few otiiers again, peculiar to North America, would find 

 their other representatives only in the region lying to the west. One or 

 two types also may be considered as cosmopolitan, Vanessa in particular; 

 while Hypatus belongs to a cosmopolitan or vagrant group, having scat- 

 tered members, closely allied, in nearly all parts of the world. There 

 would remain, however, two or three genera, the presence of which would 

 be somewhat difficidt to account for. One is Anosia ; the difficulty here 

 docs not arise from its presence in New P]ngland so much as in America, 

 since with a few other types, like it distriliuted throughout the tropics of 

 America, it belongs strictly to the Old World division of the family, the 

 great body of its relatives, which are very numerous, being found in the 

 tropics of the Old AVorld. The presence of two other genera, Enodia 

 among the satyrids and Feniseca among the coppers, is still less easily 

 understood. Their nearest allies are all found south of the tropics in the 

 Old World and the explanation of their presence, not only in the New 

 AVorld but exchisi\ely in tlie regions north of the tropics, is the puzzle. 

 Thev alone can be mentioned as widely separated in structure from their 

 immediate allies in North America and as endemic types of probably 

 great antiquity. There are, however, other genera which are of similar 

 though secondary interest, since, though not peculiar to New England 

 certainly l)ut to the north temperate zone of North America, they are 

 somewhat widely separated from their neighbors structurally. Such, 

 among the Nymphalidae, are the genera Satyrodes, Speyeria and Euphy- 

 dryas ; among the Lycaenidae, the genus Strymon ; among the Papili- 

 onidae, Jasoniades ; and among the Hesperidae, Poanes and Polites. Of 

 these it should be remarked that all but Kuphydryas find their nearest 



