GLACIAL EPOCHS AND POLAR CLIMATES. 51 



emigrated at the close of the Pliocene age. There 

 is much evidence to shov/ that the following of 

 these routes was highly improbable, if not im- 

 possible, simply because the land area of the north 

 temperate zone has undergone vast change during 

 Tertiary time, and must have had a very different 

 aspect from what it now presents. 



Let us now turn to more recent testimony. In 

 the Falkland Islands Charadrius modestus breeds, 

 and goes north to winter as far as Uruguay ; whilst 

 an allied form, C. modestus riLbecola^ breeds on 

 Tierra del Fuego, and passes as far north as Chili 

 during winter. The fact that this species has be- 

 come segregated into two races in so narrow an 

 area seems to suggest a long residence in this 

 region. In the same group of islands we also have, 

 in Tierra del Fuego, Charadrius sociabilis, with 

 the same distribution as C. ?nodestus, and Scolopax 

 frenata magellanica^ breeding in the Falklands, and 

 passing as far north as Paraguay to winter. In 

 Chili we find Himantopns brasiliensis, with a con- 

 siderable northern migration during winter; also 

 Rhynckcea semicollaris, which in summer extends 

 its range south to Magellan, and in winter north 

 to Brazil. In fact, all the species of the genus 

 Rhynchcpa appear to me to be decidedly Antarctic. 

 Their present distribution seems to admit of no 

 other conclusion. Their presence in Patagonia, 

 South Africa, Australia, and India (probably by 

 way of the Malay Archipelago, Siam, Burma, and 

 Lemuria), rather shows an Antarctic emigration than 



