SCOLOPAX. 



467 



Andes (8. jamesoni and 8. imperialis), the Southern Andes (8. stricklandi), and the 

 Pampas of South America (8. undtdata), whilst the most enterprising party found a home 

 on the Auckland Islands (8. auclclandlcci). 



It is difficult to assign an exact locality as the place where the Jack Snipe (8.gattinida) 

 was isolated and differentiated during the Post-Pliocene Glacial Epoch ; but the extent to 

 which differentiation has taken place points to complete isolation, and the small size of the 

 bird is an argument in favour of isolation on an island. The fact that its present range 

 of distribution extends from the Atlantic to the Pacific suggests an island midway between 

 the two; and none of its present winter-quarters fulfil all these conditions so well as the 

 island of Ceylon. 



The Typical Snipes seem to have been the most adventurous, possibly because their 

 original home having been, as it now is, the swamps caused them to multiply with great 

 rapidity. During the Pliocene Age they became differentiated into. Typical Snipes, the 

 creme de la creme of the genus, to all intents and purposes a circumpolar species. 

 The Post-Pliocene Glacial Period drove them south. 8. wilsoni retained the original area 

 of distribution in the New World, and is the least variable species, though its migratory 

 habits have obliged it to lengthen its wings and shorten its bill. 8. frenata is the result of 

 the surplus population which crossed the line to South America, where, not being obliged 

 to migrate, it retained its rounded wings and longer bill. In a vast continent like South 

 America it is not to be wondered at that more or less distinct local races have since 

 developed themselves. 



The different distribution of land in the Old World caused more isolation, and 

 consequently more differentiation. The present winter-quarters of the various species 

 probably represent the localities where their respective isolation and differentiation took 

 place. 8. nemoricola became a forest-bird, and was isolated on the outskirts of the 

 Himalayas ; 8. solitaria was probably developed in China ; S. (Bquatorialis crossed the Line 

 and was isolated in South Africa ; 8. gallinago was isolated in the basin of the Mediter- 

 ranean, and, being subjected to precisely the same influences as its Nearctic ally (the 

 necessity to become a migrant), slightly changed in a similar direction. 8. major was 

 isolated in East Africa, 8. slenura in India, 8. megala in the Malay Archipelago, and 

 S. australis became a migratory bird, breeding in Japan and wintering in Australia. 



The latter species, commonly known as Latham's Snipe, seems to have early become 

 more or less modified by its isolation in Japan, where it probably developed a very long 

 bill. This inference is based on the fact that its nearest allies are 8. macrodactyla in 

 Madagascar and 8. nobilis in Colombia, two species doubtfully distinct from each other. 



The explanation of the apparently extraordinary fact that two such very closely allied 

 birds inhabit such widely distant localities appears to me to be as follows : — Their nearest 

 relation is unquestionably Latham's Snipe, which occupies a locality midway between them. 

 This Snipe is a migratory bird, breeding in Japan and wintering in Australia. There 



3o 2 



Original 

 home of the 

 Jack Snipe. 



Emigrations 

 of Typical 

 Snipes. 



Remarkable 



similarity 



between 



distant 



species. 



